7.3 Tools Flashcards
1
Q
A
2
Q
Why is accurate measurement essential in aviation engineering?
A
It ensures precision and safety in engineering practices
Accurate measurements are critical for ensuring that all components function correctly and meet safety standards.
3
Q
What must be done before using any precision measuring tool?
A
Ensure it is within its calibration period
Tools must be calibrated by an approved person or organization.
4
Q
What does it mean for a tool to ‘zero’ correctly?
A
The reading on the instrument should read zero when measuring faces are closed
If zero is not achieved, the tool requires recalibrating.
5
Q
Why is calibration essential for torque wrenches?
A
It maintains accuracy and longevity
Calibration ensures compliance with stipulated standards for reliable measurements.
6
Q
What can general wear and tear do to torque wrenches?
A
It can lead to incorrect and unreliable readings
Regular calibration helps mitigate these effects.
7
Q
What is the purpose of a torque analyser?
A
To check and calibrate all types of torque wrenches and power tools
It conforms to torque tool standards ISO 6789, BS 6703, and ANSI/ASME B 107.14M.
8
Q
What units of measurement can a torque analyser display?
A
- N.m
- dN.m
- cN.m
- lbf.ft
- lbf.in
- ozf.in
- kgf.m
- kgf.cm
- gf.cm
The unit can be selected according to the operator’s requirements.
9
Q
Who performs the calibration of torque wrenches and other measuring equipment?
A
Approved organizations employing certified personnel
Ensures that calibration adheres to industry standards.
10
Q
How are pressure gauges and transmitters calibrated?
A
By hydraulic pumps using water or oil, or pressure generators using oil or gas
This method ensures accurate pressure readings.
11
Q
What is the process to recalibrate a micrometer?
A
Insert a precision block between the anvil and spindle, then align the longitudinal line with the zero mark
A special wrench is used to rotate the sleeve for calibration.
12
Q
What environmental factor can affect the calibration of a micrometer?
A
Extreme temperatures
Temperature fluctuations can impact the accuracy of the calibration process.
13
Q
What is the basic function of a screw?
A
A machined bolt with a thread cut into it that allows various types of screwdriver to turn the screw and apply torque.
14
Q
What are the main parts of a screwdriver?
A
- Tip/Blade
- Shank
- Handle
15
Q
What material is commonly used for the shank of a screwdriver?
A
Carbon steel
16
Q
What is the purpose of the handle of a screwdriver?
A
To fit the hand and provide a non-conductive material for safety.
17
Q
What are the two main classifications of screwdrivers?
A
- By type of tip
- By socket type arrangement
18
Q
What are socket drive screwdrivers used for?
A
To accept multiple screwdriver bits for greater efficiency.
19
Q
Name three types of specialized screwdrivers.
A
- Long reach screwdrivers
- Insulated (Safety) screwdrivers
- Watchmakers screwdrivers
20
Q
What is a slotted screwdriver used for?
A
Only where slotted head screws or fasteners are found.
21
Q
What is the point angle of a Phillips screwdriver?
A
30°
22
Q
Fill in the blank: Phillips screwdrivers are sized by a number with the smaller heads corresponding to the _______.
A
smaller number
23
Q
What distinguishes the Reed & Prince (Frearson) screwdriver from the Phillips screwdriver?
A
It has a pointed end and a larger angle in the V shape of 45°.
24
Q
True or False: The Posidriv screwdriver is an improved version of the Phillips screwdriver.
A
True
25
What is the naming convention for Torx screwdriver bits?
Indicated by the letter T, ranging from T1 to T100.
26
What type of screws do internal hex (Allen Key) screwdriver bits install?
Internal hex screws
27
What is the size range for Tri-wing screwdriver bits?
0 to 15
28
What is a characteristic of Torq-set screwdriver bits?
The cross is offset.
29
What is the advantage of the MorTorq screwdriver bit?
It provides full contact and allows for high torque application.
30
What type of fastener is Hi-Torque used for?
Thin aircraft skins with a flush fitting fastener.
31
What tool is used to remove tightly fastened screws or damaged screw heads?
Screw extractor
32
Fill in the blank: The screwdriver tip must fill at least _______ of the screw slot to prevent slipping.
75%
33
What must be done if a screw head has cam-out damage?
Do not attempt to install; get a new screw.
34
What are some common applications for Phillips screwdrivers in aircraft work?
* Access panels
* Floor boards
* Interior trim
35
What is the main advantage of using Torx screws?
Reduced risk of cam-out and requires less operator effort.
36
What sizes are Mortorq screwdriver bits?
PMT-000 to PMT-8 (#0 to 1” Ø fasteners)
37
What is the primary function of a screw extractor?
To apply much more force to remove a screw.
38
What is the most common hammer type that should not be used in the aircraft engineer's toolkit?
Carpenters or claw hammer
39
What are the three power sources for hammers mentioned?
* Hand powered
* Pneumatically powered
* Electrically powered
40
How are hammers classified?
* Pein
* Face
* Weight
* Shape
41
What materials are typically used for the head of a hammer?
Steel
42
What materials are used for the handle of a hammer?
* Wood
* Plastics
* Composite materials
43
What is the purpose of shock-absorbing polymers on hammer handles?
Reduce fatigue on the operator and increase comfort during use
44
What determines the type of hammer?
The pein of the hammer
45
What type of steel are Ball Pein hammers made from?
High-grade drop forged steel, fully heat-treated
46
What are the common uses for Ball Pein hammers?
* Use with cold chisels
* Punches
* Rivets
* Shaping of metal
47
What does DIN stand for in DIN hammers?
Deutsches Institut Für Normung (German Institute of Standardisation)
48
What is the primary function of a Soft Face Mallet?
Offer driving force without damaging surfaces
49
What materials are used for the faces of soft-faced mallets?
* Plastics
* Nylon
* Natural rubber
50
What is a key characteristic of a rubber mallet?
Heavier than other mallets, used to drive larger fasteners
51
What types of hammers are considered less common in aviation?
* Dead Blow hammers
* Copper hammers
* Rawhide hammers
* Sheet metal hammers
52
What should be checked before using a hammer?
* Handle is secured properly
* Face or pein are clean and free from burrs
53
What personal protective equipment (PPE) should be worn when using a hammer?
* Eye goggles
* Gloves if required
54
When striking an object with a hammer, how should the arm be positioned?
In line and effectively an extension on the hammer handle
55
What should be done if large swings are required to drive an object?
Consider replacing the hammer with a heavier one or pressing the bolt into place
56
True or False: Hammers can be used interchangeably without regard for the specific task.
False
57
What are pliers?
Pliers are a group of tools with a pair of handles joined by a fulcrum/pivot, used for gripping, bending, cutting, and twisting.
58
What materials should high-quality pliers be made of?
High-quality pliers should be made of alloy steel with induction hardened cutting edges and preferably have handles sheathed in soft plastic or rubber.
59
What are the four types of joints found in pliers?
The four types of joints are:
* Single Fixed Joint
* Toggle (Compound) Joint
* Lap Joint
* Slip Joint
60
What is the purpose of diagonal cutters or snips?
Diagonal cutters are intended for cutting wire and not for grabbing or turning objects.
61
How do diagonal cutters cut wire?
Diagonal cutters cut wire by indenting and wedging it apart rather than using a shearing action.
62
What are combination (lineman's) pliers used for?
Combination pliers are multifunctional and can hold, cut, twist, or bend materials.
63
What is the main feature of long nose pliers?
Long nose pliers have long, thin jaws that allow for greater precision in detailed work with wire.
64
What are multi-grip or swan neck pliers designed for?
Multi-grip pliers have several curved grooves for interlocking joints, allowing for the application of significant force.
65
What is the function of vice-grip pliers?
Vice-grip pliers have adjustable jaws that clamp tightly when handles are squeezed, providing substantial gripping force.
66
True or False: The term 'Mole Grip' is a correct name for vice-grip pliers.
False
67
What are circlip pliers used for?
Circlip pliers are used for fitting and removing circlips during assembly or disassembly work.
68
What is the primary use of wire locking pliers?
Wire locking pliers are used for locking safety wire in multiple locations around an aircraft.
69
Fill in the blank: Pliers can cause damage to work due to their tip jaws being _______.
serrated
70
What types of vices are commonly classified for aircraft maintenance?
The three types of vices are:
* Metalworking vices
* Hand held vices
* Machine vices
71
What are the component parts of a metalworking vice?
The component parts include:
* Fixed jaw
* Adjustable jaw
* Screw or lever
72
What is the function of a hand vice?
A hand vice is designed for holding small work pieces and can be easily moved around during operations.
73
What is the main characteristic of 'C' or 'G' clamps?
'C' or 'G' clamps have a threaded screw, a moveable jaw, and a swivel plate to prevent damage to the material being clamped.
74
What is the purpose of covering work pieces with masking tape when using clamps?
Covering work pieces with masking tape protects them from marks and damage caused by clamps.
75
What type of pliers are used for detailed work with wire?
Long nose pliers
76
What is a significant feature of machine vices?
Machine vices can be easily moved and locked down to a surface for stability during operations.
77
What is the typical size range for clamps?
Clamps vary in size from one inch (25 mm) upward.
78
What type of joint do wire locking pliers typically use?
Single joint
79
What type of action do diagonal cutters use to cut larger gauge wire?
Compound-action
80
What is the UK term for 'Wrench'?
Spanner
81
What is the US term for 'Ratchet'?
Ratchet handle
82
What material is commonly used for the construction of spanners for strength and longevity?
Chrome-Vanadium Steel
83
What are the safety standards that tools should be tested to?
DIN3118 or ASME B107.110
84
List the classifications of spanners.
* Open-end Spanner
* Ring Spanner
* Combination Spanner
* Ratchet Handles
* Sockets
* C Spanner
* Strap Wrench
85
What is an Open-end Spanner designed to fit onto?
Hexagonal nut
86
What is the typical size range for spanners measured in AF?
3/16” to 1-1/16”
87
True or False: Adjustable spanners are recommended for use on aircraft.
False
88
What type of spanner surrounds the fastener and is useful in close quarters?
Ring Spanner
89
What mechanism does a Ratchet Ring Spanner use?
Allows a ring head to turn a fastener in one direction only
90
What does a Combination Spanner incorporate at each end?
Open-end spanner and a ring spanner
91
What is the primary function of a Breaker Bar?
To 'break' the torque when removing a fastener
92
What are the two formats of sockets?
* 6 point
* 12 point
93
What is the purpose of insulated tools?
To protect against electrical shock
94
What is a Fixed C-spanner used for?
To remove/install nuts with corresponding slots
95
Describe the Adjustable C-spanner.
A spanner with a split middle connected by a pin allowing for a greater size range
96
What is a C-pin Spanner designed for?
Nuts with holes for a pin to be inserted
97
What is the function of a Strap Wrench?
To apply load on an object using friction
98
Fill in the blank: The Adjustable Spanner has one fixed jaw and the other is moved by a _______.
thumbscrew
99
What types of drive sizes are commonly found for Ratchet Handles?
* 1/4” drive
* 3/8” drive
* 1/2” drive
100
What is the unique feature of a Pin Face Spanner?
Has two pins for nuts with locating holes
101
What type of fasteners do Bi-hex Open-end Spanners and Crow Foot Spanners secure?
Bleed nipples or pipework
102
What is the primary purpose of a Ratchet Handle?
To provide a means of removal and installation of fasteners
103
What is the primary function of a Torque Wrench?
Applies a specific torque or load to a fastener such as a bolt, nut, or screw.
104
According to ISO 6789, how are torque wrenches classified?
Torque wrenches are classified into two types: Type 1 (Indicating) and Type 2 (Setting).
105
What is Type 1 Torque Wrench?
Torque wrenches that indicate the torque to the user via a mechanical scale, dial, or electronically.
106
What is Type 2 Torque Wrench?
Torque wrenches that are either fixed or adjustable to a pre-set torque value, indicating once the pre-set torque is reached.
107
What is the tolerance for Type 1 Class A torque wrenches?
±6% for ≤10 Nm.
108
What distinguishes a Ratchet Click Type Torque Wrench?
It indicates that the desired set torque has been reached by a clicking sound.
109
Fill in the blank: Torque is a rotational or twisting force intended to ______ a fastener.
[rotate or turn]
110
What units express torque measurements?
* Newton Meters (Nm)
* Pounds feet (lbs-ft)
* Pounds-inch (lbs-in)
111
What should be done when storing torque wrenches?
* Keep them in original packaging
* Store in a clean area
* Clean before returning to the box
* Turn back to the lowest setting for adjustable wrenches
* Ensure instructions are included
112
True or False: A Fixed Torque Wrench can be adjusted to different torque settings.
False
113
What is a common use for a Fixed Screwdriver?
Used for lower value torques and for tasks that are repetitive and frequent.
114
What does a Ratchet Electronic Type Torque Wrench indicate when the desired torque is achieved?
Displays a Green light, sounds an audible buzzer, and vibrates.
115
What is the recommended working range for a mechanical torque wrench?
20-80% of its full scale.
116
What is the recommended working range for an electronic torque wrench?
10-100% of its full scale.
117
What safety equipment should be worn when using a torque wrench?
At a minimum, safety goggles should be worn.
118
What should be checked before using a torque wrench?
* Inspect for damage
* Check calibration label
* Ensure torque to be applied is within range
119
What happens when the torque has been indicated by a click on a torque wrench?
STOP IMMEDIATELY.
120
What is the purpose of the clicking sound in a Ratchet Click Type Torque Wrench?
Indicates that the desired set torque has been reached.
121
What is torque often referred to as?
Moment of force.
122
What should be done with an adjustable torque wrench before storing it?
Turn the adjustment back to the lowest setting.
123
What is the purpose of an audible signal in Type 2 torque wrenches?
To indicate when the pre-set torque has been achieved.
124
Fill in the blank: The Flex Bar torque wrench is now rarely seen and is susceptible to ______.
[damage]
125
What is the advantage of an Electronic Torque Wrench?
Provides clear indication and often includes audible signals once the desired torque is achieved.
126
What should be avoided when applying torque to a fastener?
Small tightening movements
## Footnote
Smooth arc loading is recommended.
127
What action should be taken immediately after the torque has been indicated by a click?
STOP IMMEDIATELY
## Footnote
This indicates that the desired torque has been achieved.
128
What is the lever arm in the context of a torque wrench?
The length from the center of the drive holding the socket to the handle
## Footnote
Denoted as L1 nominal length.
129
What effect does adding an extension to a torque wrench have?
Increases the lever arm to L2 extended length
## Footnote
This can increase the torque setting applied.
130
What is the critical concern for an Aircraft Engineer when using a torque wrench?
Avoiding over-torquing of fasteners
## Footnote
Over-torquing can go unnoticed and lead to failures.
131
When using an extension placed at 90° to the torque wrench arm, what happens to the torque value?
The torque value specified can be used without any change
## Footnote
The center of the fastener remains on the same plane.
132
What is necessary when calculating torque for extensions at angles other than 90°?
A torque calculation must be performed
## Footnote
This involves adjusting the torque value based on the new length.
133
What does T1 represent in torque calculations?
The torque specified for the fastener
## Footnote
This is the initial torque setting before adjustments.
134
What is an alternative method some manufacturers might specify for tightening?
Torque-angle tightening method
## Footnote
This method uses an angle for final torque instead of a torque value.
135
What is the role of the torque-angle tool?
To provide an angle that has to be used for final torque
## Footnote
This is an alternative to using a torque value.
136
Fill in the blank: If an extension is added to a torque wrench, the prescribed torque must be ______.
reduced
## Footnote
This adjustment accounts for the increased lever arm.
137
What is the purpose of torque calculation apps like the Norbar Torque Wrench Extension App?
To calculate torque values when extensions are used
## Footnote
These apps help ensure correct torque settings.
138
What are the common materials used to make rules/rulers?
Tempered carbon steel, satin-finished stainless steel
## Footnote
Rules can be rigid or flexible and usually come in standard lengths of six inches and 12 inches.
139
What are the standard fractional scale divisions for an inch?
* Halves (1/2)
* Quarters (1/4)
* Eighths (1/8)
* Sixteenths (1/16)
* Thirty-seconds (1/32)
* Sixty-fourths (1/64)
## Footnote
Each division corresponds to a specific measurement in millimeters.
140
What is the primary unit of measure used in aviation?
Inch
141
What is the purpose of a flexible steel tape?
Taking measurements up to several feet
## Footnote
It has a hook on one end to hold onto corners or ledges.
142
What is a combination set used for?
* Marking gauge
* Scribing lines at a 45° angle
* Depth gauge
* Height gauge
## Footnote
It includes a level and scriber and has a head that slides along the rule.
143
What type of square is the Engineers Square also known as?
Machinists Square
144
What is the size range of common Engineers Squares?
3” to 12”
## Footnote
Sizes are also available in metric.
145
What is the purpose of a scriber?
To scribe or mark lines on metal surfaces
146
What are dividers used for?
* Scribing arcs and circles
* Measuring between points
* Transferring dimensions
## Footnote
They are difficult to use accurately when legs are widely extended.
147
What are the two common types of callipers?
* Inside
* Outside
148
What do radius gauges measure?
Inside or outside radii
149
What is the purpose of a feeler gauge?
To check interface gaps or gaps under bolt heads or nuts
150
What are the types of punches commonly used by Aircraft Engineers?
* Prick Punch
* Centre Punch
* Automatic Centre Punch
* Starting (Taper) Punch
* Pin Punch
## Footnote
Each punch has a specific use related to marking or starting holes.
151
What angle is the tip of a prick punch typically ground to?
30° or 60°
152
How is a centre punch used?
To make indentations in metal to prevent 'wander' when drilling
153
What is the function of an automatic centre punch?
To create an indentation without the use of a hammer
154
What is a starting (taper) punch used for?
To start driving out a bolt or pin
155
What is the size range for pin punches?
0.8 mm to 9.5 mm in diameter
156
What type of punch is used for the removal of roll pins?
Roll Pin Punch
157
What materials are used for punches to prevent damage in sensitive environments?
* Beryllium-Copper
* Brass
## Footnote
These materials minimize the risk of damage or sparking.
158
What should be done to a punch that has become burred over time?
It must be ground back to its original shape
## Footnote
A hand-file is recommended for softer materials.
159
True or False: A steel rule is subject to calibration.
False
160
What are the common types of aviation hand snips?
Straight, curved, and hawksbill
## Footnote
Each type serves a different purpose in cutting.
161
What is the primary use of aviation snips?
Cutting straight lines and curves in sheet metal
162
What are the colors of aviation snips and their cutting capabilities?
* Yellow: cut straight
* Green: curve right
* Red: curve left
163
When using aviation snips, how far should cuts be made from the layout line?
About 0.8 mm (1/32 inch)
164
What is the main function of saws in metalworking?
Separating materials and producing grooves and notches
165
What are the different sizes of hacksaws typically found in a workshop?
* Full size hacksaw (6 to 16 inches, common 12 inches)
* Junior hacksaw
* Mini hacksaw
166
What materials are hacksaw blades commonly made from?
High-grade tool steel or tungsten steel
167
What does the tooth pitch of a hacksaw blade indicate?
The number of teeth per inch
168
What tooth pitches are commonly available for hacksaw blades?
* 14 teeth per inch (coarse)
* 18 teeth per inch (coarse)
* 24 teeth per inch (medium)
* 32 teeth per inch (fine)
169
What is the required cutting technique when using a hacksaw?
More than one tooth must be in contact with the workpiece
170
How should a junior hacksaw blade be positioned?
Teeth facing towards the handle
171
What is the cutting direction for a mini hacksaw?
Teeth facing forward
172
What are the steps to follow when using a hacksaw?
* Select appropriate blade
* Adjust blade tension
* Clamp workpiece
* Nick the surface
* Hold saw at an angle
* Start with light strokes
* Maintain even pressure
173
What is the primary function of a file in metalworking?
To shape metal by cutting and abrasion
174
What materials are most files made from?
High-grade carbon steels
175
What are the common shapes of files?
* Rectangular
* Square
* Round
* Half-Round
176
What distinguishes a single cut file from a double cut file?
Single cut has one row of parallel teeth; double cut has two crossing rows
177
What does the grade of cut on a file indicate?
The strength of cut based on the pitch of the teeth
178
List the common grades of cut for files.
* Bastard Cut
* Second Cut
* Smooth Cut
* Rasp Cut
179
What is the importance of file length in a workshop?
Length affects usability and is typically between 100-300mm
180
What care should be taken for files to prevent rusting?
Store in a clean dry environment and apply a light coating of oil
181
What should be checked on a file before use?
Handle for looseness, splits, or defects
182
What is a key technique for filing effectively?
Keep even pressure on the file during use
183
What are the three main filing techniques?
* Straight (Forward) Filing
* Cross Filing
* Draw Filing
184
True or False: The forward stroke of a file is the only cutting stroke.
True
185
Fill in the blank: Files should be cleaned using a _______.
Wire Brush File Card Cleaner
186
What is Straight (Forward) Filing?
A filing method used in a straight back and forth motion, aligned with the edge of the sheet metal.
187
What is Cross Filing?
A filing technique where the file is used at an angle across the workpiece, suited for thicker pieces of metal.
188
What is Draw Filing?
A method for achieving a smooth finish by moving the file sideways back and forth on the workpiece.
189
How should one file a rounded surface?
Start with the point of the file inclined downward at approximately a 45° angle and use a rocking chair motion.
190
What is the purpose of de-burring?
To remove fine slivers of metal hanging onto the edge of the material after filing.
191
True or False: Every cutting operation on sheet metal leaves burrs and/or slivers.
True
192
What can burrs and slivers cause?
Scratches and marks on parts, preventing proper fitting and causing personal injuries.
193
What tool should be used to remove burrs?
A de-burring tool.
194
Fill in the blank: The de-burring tool's blade is aligned with the _______ of the workpiece to be de-burred.
[edge]
195
What is the common method for optimal results when using a de-burring tool?
Apply steady motion and light pressure while moving along the surface.
196
What is the primary purpose of drilling tools in aircraft engineering?
To drill holes in airframe structures
## Footnote
Drilling is a common operation for aircraft engineers.
197
What distinguishes a drill from a drill bit?
A drill is the tool that applies power, while the drill bit is the cutting tool that does the drilling
## Footnote
Common terminology in the workplace may blur this distinction.
198
What are the main types of drills commonly used in aviation?
* Hand Drills
* Pneumatic Drills
* Electric Drills
## Footnote
Pneumatic drills are preferred for safety reasons.
199
What is a Hand Brace used for in aviation?
To aid in the removal of screws by applying greater torque
## Footnote
Mainly used in carpentry, not aviation.
200
List the types of pneumatic drills mentioned.
* Pistol Grip Drill
* Straight Drill
* Right-angle Drill
* 45° Angle Drill
## Footnote
Variations may exist depending on task requirements.
201
What is a Drill Press also known as?
Pillar Drill or Bench Drill
## Footnote
Commonly used in workshops away from aircraft.
202
What is the risk associated with drill bits in the workplace?
They can cause Foreign Object Damage (FOD) if dropped or lost
## Footnote
Proper care and accounting for drill bits is crucial.
203
What are the two main types of drill bits referenced for use in aircraft maintenance?
* Twist Drills
* Countersink Tooling
## Footnote
These are the most commonly found types.
204
What is the function of the shank in a drill bit?
To fit into the drilling machine's chuck
## Footnote
Shanks can be plain or tapered.
205
What is the purpose of flutes in a drill bit?
To allow removal of chips and cutting fluid to reach the cutting lips
## Footnote
Helical grooves cut in the body of the drill serve this purpose.
206
Define 'margin' as it pertains to drill bits.
The narrow surface along the flutes that keeps the drill aligned
## Footnote
It determines the size of the drill.
207
What does the point of a drill consist of?
* Cutting Edge (lips)
* Flank
* Face
* Web
* Chisel Edge
## Footnote
Each part plays a role in the drilling process.
208
What is the typical point angle for drilling Aluminium and Mild Steel?
118°
## Footnote
This angle is commonly used for these materials.
209
What are the categories of drill web thickness?
* Light
* Medium
* Heavy
## Footnote
Most aviation engineers use Light type drills.
210
What is a Split Point Twist Drill Bit designed to do?
Reduce wandering during initial contact with the material
## Footnote
It enhances drilling efficiency and reduces heat.
211
What is the function of a countersink tool?
To create a depression for fastener heads
## Footnote
Used to ensure fasteners sit flush with the surface.
212
How does a Microstop Countersink Tool improve countersinking?
Controls depth and keeps the cutter perpendicular to the work surface
## Footnote
It is the most efficient countersinking tool.
213
What is spot facing?
Cutting a flat area for a bolt head or nut on an uneven surface
## Footnote
It is typically done using a pillar drill.
214
What is the purpose of a reamer?
To finish a drilled hole to a precise size
## Footnote
Used after drilling for enhanced accuracy.
215
What is counter-boring?
When the surface is removed beyond what is required to provide a flat surface
216
What is the purpose of a reamer?
To finish a drilled hole to the exact size, producing a smooth finish
217
What are the two main types of reamers?
* Hand Reamers
* Machine (Chucking) Reamers
218
What materials can reamers be made from?
* Carbon tool steel
* High speed steel (HSS)
219
How do high speed steel reamer blades compare to carbon steel blades?
High speed steel reamer blades lose their sharpness quicker than those made of carbon steel
220
Why must reamer blades be handled carefully?
They are hardened to the point of being brittle and can chip
221
What is the function of the grooves on straight reamers?
To provide a way for chips to escape and a channel for lubricant to reach the cutting edge
222
What angle are the cutting edges of a reamer typically ground to?
45° ± 5°
223
True or False: Reamer flutes are designed to remove chips like a drill.
False
224
What is the function of a hand reamer's square shank?
To fit into a tap wrench for applying pressure
225
What should be done to ensure the reamer is held straight during cutting?
Place it in the hole, turn slightly with the wrench, and view for alignment
226
What is the unique feature of tapered reamers?
The parallel part extends only a short distance
227
What is the advantage of using an adjustable reamer?
Can smooth bore walls of a drilled hole when precise sizing is necessary
228
What range of sizes do adjustable reamers typically cover?
From 6.35 mm (1⁄4 inch) to 25.4 mm (1 inch) in 0.08 mm (1⁄32 inch) increments
229
What is required to adjust an adjustable reamer?
A spanner and micrometer
230
How is a machine reamer driven?
Using a morse tapered shank fitted into a sleeve (Arbor)
231
What type of reamer is suited for drill presses?
Straight shank reamer
232
What is the difference between straight fluted reamers and spiral fluted reamers?
* Straight fluted: less expensive
* Spiral fluted: less tendency to chatter
233
What are the essential safety precautions when drilling?
* Use safety glasses
* Remove the chuck key
* Use drill stops
* Limit drill speed
* Use sharp drills
* Select appropriate drill motor
* Prevent hair entanglement
234
What is the use of a tap in threading?
To cut threads on the inside of a hole
235
What is a die used for?
To cut external threads on a round bar
236
What are the three types of taps in a hand tap set?
* Taper tap
* Plug tap
* Bottoming tap
237
What is the function of a taper tap?
To begin the tapping process with a tapered back for six to seven threads
238
What is the purpose of a bottoming tap?
To cut full threads to the bottom of a blind hole
239
What are the two general types of dies?
* Solid dies
* Adjustable dies
240
What is the function of the stock in threading?
To hold and turn a threading die when producing external threads by hand
241
What is the function of a pillar drill?
To rotate a drill bit and press it against a work piece to drill a hole.
242
What type of power tools are included in electrically driven power tools?
Pillar Drill (Drill Press), Abrasive Wheels.
243
What are the safety precautions for using powered tools?
* Keep tools in good working order
* Use the right tool for the job
* Examine each tool for damage before use
* Operate according to manufacturer's instructions
* Provide and use proper PPE.
244
True or False: It is acceptable to use power tools in damp or explosive environments.
False.
245
What should be done before using an abrasive wheel?
Inspect it closely for cracks or defects.
246
What is a key feature of a bench-mounted pillar drill?
Usually belt driven with a three jaw chuck.
247
Fill in the blank: Electric tools must have a _______ or be double insulated.
three-wire cord with ground.
248
What is the recommended method for securing a work piece on a pillar drill?
Using a vice, clamps, or dogs.
249
What happens if the drill speed is too fast?
The cutting edges of the drill can dull rapidly.
250
What type of lubricant is recommended for mild steel when drilling?
Soluble Oil.
251
True or False: It is safe to carry a tool by the electrical wire.
False.
252
What should be done if a portable electric tool is damaged?
Remove it from use immediately and tag 'Do Not Use.'
253
What is the potential hazard of using electric tools?
Electrocution.
254
What should be done with the drill bit during operation to prevent breakage?
Ease off pressure when the drill point feels likely to break through.
255
What is the function of a safety guard on a powered grinder?
To protect workers from the moving wheel surface and flying fragments.
256
What should be checked before starting a drilling operation?
Ensure the work piece is secured and in the correct position.
257
What is a common feature of a floor-mounted pillar drill?
It is bolted to the floor and can have a chuck capacity of 65 mm.
258
Drilling with a speed that is too slow can result in _______.
Breaking the drill bit.
259
What is the importance of clamping a work piece?
To prevent inaccurate work and injuries to the operator.
260
What should be done if an abrasive wheel sounds cracked or dead?
It must not be used.
261
What is the maximum RPM for drilling small diameter holes in brass?
3000 RPM.
262
What type of safety equipment should be worn when operating power tools?
Appropriate PPE, including safety glasses and gloves.
263
What is the purpose of using lubricants while drilling?
To keep the drill cool and assist swarf to escape.
264
What should the operator do when the drill bit is near the far side of the material?
Be prepared for the drill to snag and release pressure immediately.
265
What is the consequence of a shattered abrasive wheel?
It can harm any person near the grinder and result in serious injury.
266
What is typically mounted to a bench or floor and fitted with a grinding wheel on each end of the shaft?
A bench or pedestal grinder
## Footnote
The grinder is enclosed by a metal guard to prevent shattering of the abrasive wheel.
267
What is a key safety warning regarding the use of abrasive wheels?
An abrasive wheel can shatter when running at high speed
## Footnote
This can result in serious injuries or death.
268
What personal protective equipment (PPE) should be worn when operating a bench or pedestal grinder?
Appropriate PPE
## Footnote
This is essential for safety during grinding operations.
269
What should be done frequently to prevent overheating when grinding a centre punch?
Quench the punch frequently
## Footnote
This prevents softening of the metal.
270
What is the main advantage of pneumatic tools over electric tools in aviation maintenance?
Safety
## Footnote
Pneumatic tools reduce the risk of sparks that can ignite flammable materials.
271
What is the typical air supply pressure for pneumatic tools?
90-110 PSI
## Footnote
Higher pressures may also be seen in facilities.
272
What is a common source for the air supply to pneumatic tools?
An electrically driven air compressor
## Footnote
The compressor is usually located outside the facility.
273
What must be done regularly to maintain air supply systems for pneumatic tools?
Drain water from the air supply regulator and traps
## Footnote
Moisture can be harmful to the compressor and tools.
274
What feature allows pneumatic hand drills to control their speed?
Varying trigger pressure
## Footnote
This allows for slow, intermediate, or high-speed operation.
275
What type of drill is most commonly used for drilling aircraft sheet metal?
Hand held pneumatic drills
## Footnote
They provide control and adequate torque.
276
What are the two most often used drill motors?
* Pistol grip drills
* Straight drills
## Footnote
These drills are available in various sizes and capacities.
277
What is a unique feature of angled drills?
Designed to operate in tight or limited-access places
## Footnote
Available head angles include 30°, 45°, and 90°.
278
What is the purpose of a drill stop?
Regulates hole depth, cushions breakthrough, eliminates surface marks, and reduces drill breakage
## Footnote
It locks onto the drill with a set screw.
279
What does a drill guide do?
Keeps the drill at 90° to the skin surface
## Footnote
It consists of a clear plastic housing and hardened steel bushing.
280
What is the function of a hole finder?
Helps locate holes in a new skin when replacing old skin
## Footnote
It aligns the drill with existing holes in the structure.
281
What is a critical safety warning regarding workpieces while hand drilling?
Never hold a work piece by hand while hand drilling
## Footnote
This can result in serious injuries if a drill breaks.
282
What type of pneumatic tool is commonly used for airframe repair work?
Pneumatic rivet gun
## Footnote
It is available in various sizes and operates at specific air pressures.
283
What type of pneumatic tool uses a piston to squeeze rivets?
Rivet squeezer
## Footnote
It requires correct adaptors called dies.
284
What is the purpose of a pneumatic blind rivet puller?
Inserts blind rivets and pulls the mandrel until it shears
## Footnote
It uses interchangeable nose pieces for different rivet types.
285
What does a rivet shaver do?
Trims protruding mandrels of rivets
## Footnote
It ensures the head of the rivet is not damaged during the shaving process.
286
What are the main precision measuring tools used in aircraft maintenance?
Micrometers, Vernier Callipers, Dial indicators, Go/No-Go gauges
## Footnote
These tools are essential for ensuring the correct fit of fasteners and components.
287
What is the purpose of taking precision measurements in aircraft maintenance?
To ensure that the fit of fasteners and components is correct and to monitor in-service limits
## Footnote
Accurate measurements are essential when installing parts with specified dimensional tolerances.
288
What should be done before using any precision measuring instrument?
A check of its accuracy by zeroing the instrument
## Footnote
Instruments that fail to zero correctly need to be recalibrated under controlled conditions.
289
What are micrometers used for?
To take precise measurements of small dimensions
## Footnote
Micrometers are commonly used for measuring thickness and diameters.
290
Fill in the blank: Micrometer readings require careful _______.
handling
291
What is a key characteristic of Vernier Callipers?
They allow for measurements of internal and external dimensions
## Footnote
Vernier Callipers can also measure depths.
292
What is essential when taking Vernier Calliper readings?
Proper alignment and reading of the scale
## Footnote
Misalignment can lead to inaccurate measurements.
293
What is the function of a Vernier height gauge?
To measure the height of objects accurately
## Footnote
It is commonly used in machining and assembly processes.
294
What does a dial indicator measure?
Small distances or changes in position
## Footnote
Dial indicators are often used to check the runout of rotating parts.
295
True or False: Go/No-Go gauges are used to measure whether a part is within specified tolerances.
True
296
What is the importance of monitoring wear limits in aircraft components?
To ensure safety and proper functioning of the aircraft
## Footnote
Exceeding wear limits can lead to component failure.
297
Fill in the blank: Taking an accurate measurement is essential for _______ tolerance fits.
close
298
What is a micrometer used for?
To measure parts to the second decimal place in the metric system or the third place in the imperial system.
299
List the four types of micrometers.
* Internal (inside) micrometer
* External (outside) micrometer
* Depth micrometer
* Thread micrometer
300
Describe the basic structure of a micrometer.
A semi-circular frame with a cylindrical extension (barrel) at its right end and hardened anvils inside at the left end.
301
What is the pitch of the screw in a metric micrometer?
0.5 mm
302
How is measurement taken in a micrometer?
Between the face of the anvil and the end of the spindle.
303
What is the range of a standard metric micrometer?
25 mm
304
What is the pitch of the screw thread in an imperial micrometer?
40 threads per inch
305
How much does one revolution of the thimble advance the spindle face in an imperial micrometer?
1/40 inch or 0.025 inch
306
How is the reading line on the sleeve of an imperial micrometer divided?
Into 40 equal parts
307
What does every fourth line on the sleeve of an imperial micrometer represent?
One hundred thousandths
308
What is the purpose of a calibration check on a micrometer?
To verify accuracy and make necessary adjustments.
309
What is a gauge block used for in micrometer calibration?
To check and readjust the micrometer's accuracy.
310
What is the function of an internal micrometer?
To measure the inner diameter of holes.
311
What does a three-point internal micrometer do?
Provides more accuracy to internal measurements of bores.
312
What does a depth micrometer measure?
Depth relative to the base plate.
313
How is the screw in a metric micrometer calibrated?
It has a pitch of 0.5 mm, opening 0.5 mm for each revolution.
314
How is a reading taken on a metric micrometer?
Add the number of hundredths indicated on the thimble to the millimetres and half-millimetres uncovered on the barrel.
315
What is the accuracy of a micrometer that can measure to 0.001 mm?
0.001 mm or 0.0001 inch
316
What must be checked before handling a micrometer?
Pre-use checks, calibration sticker, obvious damage, and zero setting.
317
Fill in the blank: The bevelled edge of the thimble in an imperial micrometer is divided into _______ equal parts.
25
318
True or False: The rim of the thimble on a metric micrometer is divided into 50 equal divisions.
True
319
What is a ratchet stop used for in micrometer operation?
To clamp the spindle against the subject without over-tightening.
320
What is a Vernier Caliper?
A tool used to make accurate internal, external, and depth measurements faster than a micrometer.
321
What are the three common types of calipers?
* Vernier Slide Caliper
* Digital Caliper
* Dial Caliper
322
What are the two main parts of a Vernier slide caliper?
* A fixed jaw with a measurement scale
* A moveable jaw with a Vernier scale
323
What does the Vernier scale allow?
It allows for more precise readings by comparing two lines of known length.
324
What is the accuracy of a 1/10 Vernier scale caliper?
0.1 mm
325
What is the accuracy of a 1/20 Vernier scale caliper?
0.05 mm
326
What is the accuracy of a 1/50 Vernier scale caliper?
0.02 mm
327
How is the main scale of the imperial Vernier caliper divided?
Divided into tenths, further subdivided by four.
328
What is the value of each division on the imperial Vernier scale?
0.001 inches
329
What is the first step in taking a Vernier caliper reading?
Count the total length indicated on the main scale.
330
How should you prepare a Vernier caliper before use?
Perform a zero error check.
331
What is the key advantage of a digital caliper?
Easy and quick to read with no risk of parallax error.
332
What are some disadvantages of digital calipers?
* Expensive to purchase
* Susceptible to environmental damage
* Usually require replacement if they fail
333
What system does a dial caliper use to indicate measurements?
A rack and pinion system.
334
What is a disadvantage of dial calipers?
They are more difficult to read than other types.
335
Fill in the blank: The fixed jaw of a Vernier caliper is located at _______.
one end of the beam.
336
True or False: Most Vernier calipers have an imperial scale on the upper section and a metric scale on the lower section.
True
337
What must be done if the zero error check is not satisfactory?
The instrument should be rejected and sent out for calibration.
338
What is the purpose of the fine adjuster on a Vernier caliper?
To achieve the final measurement.
339
How is the total reading calculated when using a Vernier caliper?
Add the main scale reading to the Vernier scale reading.
340
What is the primary function of a vernier height gauge?
To measure absolute height above a datum surface and differences in height between parts.
341
What type of surfaces is a vernier height gauge typically used on?
Surface plate or marking out table.
342
What feature does the vernier height gauge often include?
Dual scale with both millimetre and inch measurements.
343
What must be ensured for accurate measurements when using a height gauge?
The base of the height gauge, the surface table, and the workpiece must be perfectly clean.
344
What is used for making accurate markings on components with a height gauge?
A finger with a sharp ground edge.
345
What must be done with the height gauge after use?
Carefully return it to proper storage.
346
How can a vernier height gauge be used to measure the underside of a feature?
By reversing the finger.
347
What additional allowance must be added when measuring to the underside?
The height of the finger arm plus twice the height of the finger, that is X + 2Y mm.
348
Fill in the blank: The vernier height gauge has a vertical beam scale fixed to a _______.
[flat base]
349
True or False: The vernier height gauge can only measure absolute height.
False
350
What does DTI stand for?
Dial Test Indicator
## Footnote
Dial Test Indicator is a high-precision measurement tool used for alignment and surface smoothness.
351
What is the accuracy of a dial test indicator?
0.01 mm or 0.001"
352
What are the two types of Dial Test Indicators?
* Plunger DTI
* Lever DTI
353
What is the typical measurement range of dial indicators?
0.25 mm to 300 mm (0.015 in to 12.0 in)
354
What is the graduation range for dial indicators?
0.001 mm to 0.01 mm or 0.00005 in to 0.001 in
355
What is a common support for a Dial Test Indicator?
Magnetic stand
## Footnote
Other arrangements like clamps can also be used.
356
Describe the main components of a plunger DTI.
* Graduated dial
* Needle driven by a clockwork mechanism
* Smaller embedded clock face
* Spring-loaded plunger
357
What is the function of the limit indicators on a DTI?
To set specific measurement limits on the dial face.
358
How does a lever DTI differ from a plunger DTI in operation?
The lever DTI measures deflection by swinging in an arc rather than retracting.
359
What types of measurement can a lever DTI perform?
Measurements in narrow grooves and small bores.
360
What materials are commonly used for contact points in lever DTIs?
* Steel (alloy tool steel or HSS)
* Carbides (like tungsten carbide)
* Ruby
* Teflon or PVC
361
What is the first step in operating a DTI?
Mount the dial test indicator onto a stand.
362
What should you do after pressing the spindle extension against the surface?
Lock the indicator into place and observe the reading on the dial.
363
What do Go/No-go gauges help determine?
Whether parts are within specified limits.
364
What is the purpose of the two sets of jaws in Go/No-go gauges?
One set is slightly over size (go size) and the other is slightly under size (no-go size).
365
What does it mean if a part passes through both gaps of a Go/No-go gauge?
The part is undersized.
366
Fill in the blank: The difference in dimensions between the high size and the low size represents the _______.
acceptable tolerance for a part.
367
True or False: Go/No-go gauges can be adjustable or non-adjustable.
True
368
What is a typical application for Go/No-go gauges?
Checking control cable terminal fittings after swaging.
369
What is the importance of lubrication in aircraft?
Lubrication is critical to the safe operation of any aircraft and its systems
370
What is the term used for replenishing and checking aircraft systems?
Servicing
371
Where can information about servicing operations for a specific aircraft be found?
Chapter 12 of the Aircraft Maintenance Manual
372
What must be adhered to during aircraft servicing?
Mandatory tasks and safety instructions
373
What must be done with hoses from liquid and gas servicing trolleys when not in use?
They must be blanked and checked for cleanliness and serviceability
374
What type of fire extinguishers must be accessible during aircraft servicing?
Fire extinguishers suitable for fuel and electrical fires
375
What are the three categories of lubricants used on aircraft?
* Greases
* Oils
* Speciality Lubricants
376
What areas can the lubricants be used in?
* Airframe systems (Hydraulic, Flight Controls, Landing Gear etc.)
* Engine & Gearbox systems
377
What must be done to the lubrication equipment before use?
It must be kept clean and filled with clean/new lubricant
378
What personal protective equipment (PPE) should be worn when applying lubricants?
Protective gloves, eye protection, face masks, and body coverings
379
What is a Material Safety Data Sheet (MSDS)?
A document that contains safety information regarding specific lubricants
380
What happens if opened containers of lubricants are left out?
They should be disposed of to prevent contamination
381
What are the common methods of applying lubricants?
* Grease gun
* Hand application
* Brush
* Oil can
382
What is a grease nipple?
A one-way valve that isolates grease in the channel/line for lubrication
383
What type of grease fitting is most commonly used on aircraft?
Zerk grease nipples
384
What must be done before attaching the grease adapter to a grease nipple?
The nipple must be cleaned
385
What is the purpose of a pneumatic grease pump?
To allow quicker application of grease under constant pressure
386
What type of oils can be used in aircraft?
* General servicing oil
* Speciality lubricants
* Hydraulic oils
* Engine oils
387
What type of hydraulic oils are commonly used on aircraft?
* Mineral based oil
* Ester phosphate based oil
388
What is the method used to top up a mineral based fluid system?
Pouring directly into the reservoir
389
What is required to open a can for direct fill method?
A can opener
390
What is the common hand pump used to top up systems for oils?
Risbridger
391
True or False: All grease guns must be dedicated to a specific grease type.
True
392
Fill in the blank: The _______ is used to agitate the lubricant in an aerosol can.
pea
393
What must be done before applying speciality lubricants from an aerosol can?
Shake the can until the 'pea' can be heard moving
394
What is the primary function of an ammeter?
To measure electric current in amperes (A)
## Footnote
Smaller values of current can be measured using a milliammeter or microammeter.
395
What is the main purpose of a voltmeter?
To measure the voltage or potential difference between two points in an electric circuit
## Footnote
Voltmeters have very high resistance to minimize current flow through the voltmeter.
396
Define ohmmeter.
A device used to measure resistance, typically in ohms
## Footnote
An ohmmeter uses a small battery to create a current for measurement.
397
What is a digital multimeter?
An instrument that can measure multiple electrical properties, such as voltage, current, and resistance
## Footnote
Digital multimeters provide readings in numerical form.
398
What does an amp clamp meter do?
Measures current flowing through a conductor without direct connection
## Footnote
It uses electromagnetic principles to measure current.
399
What are the most important electrical measurements?
* Current
* Voltage
* Resistance
* Power
## Footnote
These measurements are essential for aircraft maintenance and troubleshooting.
400
What principle do most electrical measurements rely on?
Electromagnetism
## Footnote
This principle is based on the relationship between current, voltage, resistance, and power.
401
What is the Permanent Magnet Moving Coil (PMMC) meter?
The most widely used type of meter for measuring electrical values
## Footnote
It operates on the principle of a moving coil within a magnetic field.
402
How does the PMMC meter's pointer deflection relate to current?
The pointer deflects an amount proportional to the current flowing through the moving coil
## Footnote
The stronger the magnetic field, the farther the coil moves.
403
What is 'full-scale current'?
The amount of current that must flow through the meter coil to cause full-scale deflection
## Footnote
It is critical for determining meter sensitivity.
404
How is meter sensitivity defined?
The reciprocal value of the full-scale current, representing resistance needed to produce full-scale current
## Footnote
For example, a meter requiring 1 mA has a sensitivity of 1000 ohms per volt.
405
What is the role of a shunt in an ammeter?
To allow the meter to measure higher currents by bypassing most of the current
## Footnote
Shunts are designed to carry a large proportion of the current.
406
What is a multi-range ammeter?
An ammeter designed to measure multiple current ranges by using different shunt resistors
## Footnote
Users can select the desired range via a switch.
407
Describe a DC voltmeter's connection in a circuit.
It is connected in parallel with the load to measure voltage
## Footnote
The voltmeter must be connected with the correct polarity.
408
What is a multiplier resistor in a voltmeter?
A resistor placed in series with the meter movement to limit current for full-scale deflection
## Footnote
It helps in extending the measurement range of the voltmeter.
409
What must be done before using an ohmmeter?
Calibrate the device by shorting the test leads
## Footnote
Calibration ensures accurate readings for unknown resistances.
410
What happens to the ohmmeter's pointer when the test leads are separated?
The pointer returns to the left side of the scale (infinity)
## Footnote
This indicates no current flow through the meter.
411
True or False: Voltmeters can be used to measure AC voltage.
False
## Footnote
DC voltmeters should not be used for AC voltage measurements.
412
What must be done to the test leads after using an ohmmeter?
Remove the test leads to prevent accidental discharge of the ohmmeter battery
## Footnote
This is important due to high internal current when short-circuiting.
413
What happens to the pointer of an ohmmeter when the test leads are separated?
The pointer will return to the left side of the scale (infinity)
## Footnote
This is due to the interruption of current and spring tension acting on the movable coil assembly.
414
How is the indication of an ohmmeter characterized compared to voltage and current meters?
The indication is 'backwards', with maximum indication (infinity) on the left
## Footnote
Voltage and current meters have zero at the left of their scales.
415
What position must the power switch of the circuit be in when measuring resistance with an ohmmeter?
The power switch must be in the Off position
## Footnote
This prevents damage to the meter movement.
416
In a circuit measured by an ohmmeter, what does the amount of current that flows through the meter coil depend on?
The total resistance of resistors R1 and R2 and the resistance of the meter
## Footnote
The meter has been pre-adjusted for zero.
417
What is the effect of replacing resistors R1 or R2 with larger value resistors in an ohmmeter circuit?
The current flow in the moving coil of the meter would decrease, resulting in further decreased deflection
## Footnote
The scale indication would read a higher circuit resistance.
418
True or False: Ohmmeters can be connected to an energized circuit.
False
## Footnote
Any voltage applied to the test leads of an ohmmeter invalidates its reading.
419
What is the nature of the ohmmeter scale?
The scale is very non-linear and reversed compared to voltmeters and ammeters
## Footnote
This is due to the current-operated nature of the meter.
420
What should be done to obtain the most accurate measurement of resistance using an ohmmeter?
Use a scale that results in a pointer deflection in the centre third of the dial
## Footnote
The scale has numbers that are widely separated at the low-range end.
421
What are the typical operational ranges indicated on a practical ohmmeter?
R × 1, R × 10, R × 100, R × 1 000, R × 10k, R × 100k
## Footnote
The reading on the ohmmeter scale is multiplied by the factor indicated by the range setting.
422
How does a shunt ohmmeter differ from a series ohmmeter?
In a shunt ohmmeter, the resistance to be measured is in parallel with the meter movement
## Footnote
In a series ohmmeter, the resistance is in series with the internal resistors.
423
What is a safety ohmmeter designed for?
Testing resistance in volatile and explosive devices
## Footnote
It uses a very small current for testing resistance.
424
What happens when a DC meter is connected to an AC circuit?
It indicates zero
## Footnote
This is because the meter movement is restricted to direct current.
425
What is the purpose of a rectifier in measuring AC with a moving coil meter?
To convert AC to DC
## Footnote
A full-wave rectifier is preferred for higher sensitivity.
426
What is the effective value (RMS value) used for in AC meters?
It represents the average value of the pulsating DC to which the meter is reacting
## Footnote
The meter movement reacts to the average value of half of the sine wave.
427
What is a multimeter?
A device that can function as a voltmeter, ammeter, or ohmmeter
## Footnote
It connects to different external resistor networks.
428
What is the common use of a Digital Multimeter?
For field service technicians and general purpose electronics work
## Footnote
It offers convenient one-handed operation and various measurement capabilities.
429
When connecting test leads to a circuit with a multimeter, which lead should be connected first?
Connect the Common (COM) test lead before connecting the live lead
## Footnote
This is important for safety.
430
What is a current clamp?
An electrical device that clamps around a conductor to measure current without physical contact
## Footnote
It operates on the principle of a current transformer.
431
What precautions must be taken when using electrical measuring instruments?
Use a meter that meets safety standards, check calibration, inspect test leads, and use proper function and range
## Footnote
These precautions minimize the risk of electric shock and equipment damage.
