TPC 204 Flashcards
Digital meters are named such because:
Their internal circuits carry signals consisting of 1’s and 0’s
An ADC (ANALOG TO DIGITAL CONVERTER) is an essential part of:
All digital meters
Dual slope integrators are found in certain kinds of:
ADC’S
In order to generate a display, a digital meter needs a _______ processor, an ADC and a readout control.
Signal
All integrating ADC’S count the time it takes to charge or discharge a capacitor to a reference:
Voltage
LCD’S (Liquid crystal displays) make better meter displays than LED’s because of their:
Low energy requirement
What is usually expressed as plus or minus some percentage and expresses a meters maximum and minimum expected error?
Accuracy
D’Arsonval movements are used in ______ meters
Analog
Ohm per volt is the measurement unit used to express a meters:
Sensitivity
A parallel leg or branch added around an analog meter movement is known as a:
Shunt
The purpose of a make then break switch is to:
Protect the meter movement from overcurrent
You will destroy an analog ammeter if you connect it in:
Parallel instead of series
To connect an ammeter to a circuit, you need to:
Open the circuit
PMMC galvanometer movement for DC can be converted to measure AC with the addition of a:
Rectifier
The best way to take an ammeter reading on a live circuit is with a clamp on ammeter because you don’t have to:
Break into the circuit
An accurate wattmeter will always show the true power consumed, which takes into account the power losses due to:
The power factor
An internal variable resistor is needed in an ohmeter to:
Compensate for aging batteries
The jaws of a clamp on ammeter serve as a:
Transformer secondary
Use clips on the end of voltmeter leads whenever:
Voltage levels are high
Circuit resistance is measured by an:
Ohmeter
The current flowing through an ohmeter is usually very small, on the order of:
Mircoamperes
The main tests you are likely to perform using a megohmeter are for continuity, shorts, grounds and:
Insulation condition
To test the condition of the insulation on motor windings, use a:
Megohmeter
Shorted capacitors exhibit _______ resistance when tested with a megohmeter.
Little to no
When you need to measure a very small resistance, use a _______ ohmeter. When you need to measure larger resistances, use a _______.
Shunt; series ohmeter
Dual shunts in an ohmeter provide:
Dual range capabilities
VOM stands for:
Volt-ohm-miliameter
The main advantage of an analog/digital multimeter is that it can allow you to:
Spot trends more easily than with a DMM
When using a multimeter to measure voltage, what should you do after turning on the device and turning the range selector to its highest voltage?
Check the meter on a known source
Current and voltage readings taken on the far right of the meter scale provide greater:
Accuracy
Graphical multimeters can perform functions that standard digital meters cannot, such as:
Displaying transients
In the GLITCH CAPTURE MODE, the meter is set so that you can view:
Transient spikes
You should use a current probe with a multimeter whenever you need to:
Measure high magnitude current
Using a GMM in TREND mode, you can monitor:
Line voltage for sags and surges
A chief cause of
catastrophic meter failure is usually an:
Unexpected voltage
In a CAT III installation category, you would expect to find:
Three phase motors and adjustable speed drives
Transducers may be attached to an oscilloscope in order to:
Measure different kinds of signals
Inscribed on the screen of most oscilloscopes is grid like pattern, called a:
Graticule
If an oscilloscope doesn’t have a free running sweep, it will have a:
Triggered sweep
A dual trace oscilloscope is used to:
Display two wave forms at once
Regardless of whether an oscilloscope is analog or digital, single or dual trace, it can still be either a real time oscilloscope or a:
Sampling oscilloscope
Most oscilloscopes can also fill in the missing parts of a wave between the sample points. This is called:
Interpolation
Slope and trigger controls give you control over exactly where in the waveform you want the screen display to:
Begin
An attenuated probe is used to minimize the effects of:
Circuit loading
Square wave signals are used in oscilloscopes to:
Compensate the probe
Strong harmonics of the original voltage sine wave appear in an AC Power line caused by:
Non-linear loads
All meters have one thing in common. They all have an internal ______ to which measured values are compared.
Standard
