Instrumentation Flashcards
What is a Voltmeter used for
INDICATION OF BATTERY CONDITION
The circuit is said to be what when voltage is measured of the battery when not under load
OPEN CIRCUIT
The circuit is said to be what when voltage is measured of the battery when under load
CLOSED CIRCUIT
What are the 2 types of ammeter
- Standard
- Centre-zero
What is the significance of a centre zero ammeter’s needle being to the left of center ( - )
Alternator unable to supply all power demands
Battery is discharging
If the needle of a centre zero ammeter is to the right ( + ) what does this signify
Alternator supplying power to meet demands
Battery is charging
What are the definitions of the colour coded opearting bands on an instrument gauge;
GREEN
AMBER
RED
- Green - Normal operating range
- Amber - Caution range. Use for certain period of time
- Red - Absolute limit of operation
What are 3 devices capable of measuring pressure and used internally in gauges to present a read out by moving an arm or pointer
- Aneroid Capsule
- Bellows
- Bourdon Tube
what does an aneroid capsule look like and how does it function
- Flat “can”, thin metal
- Pressure causes height to change
What does a Bellows guage look like and how does it function
- Stacked can (looks like bellows)
- Can change dimensions
What does a Bourdon Tube look like and how does it function
- Flat curved tube
- Tries to straighten under pressure
Assuming situation does not change, what is indicated by
Normal Oil pressure, High or Low Temperature
MALFUNCTIONING OIL TEMP GAUGE
Assuming situation does not change, what is indicated by
High or Low Oil Pressure, Normal Oil Temperature
MALFUNCTIONING OIL PRESSURE GAUGE
Assuming situation does not change, what is indicated by
Low Oil Pressure, High Oil Temperature
OIL BEING LOST
Remaining oil has less time to cool
Remaining oil thinner, further reducing pressure
What are 2 methods for determining fuel levels in the fuel tank
- Float
- Capacitance
