UNIT 11 Flashcards
True or false: The draft gauge should only be stored in a vehicle so that it is readily available when needed.
False
What are three temperature reference points for checking temperature measuring instruments?
Water boiling point (212°F), Body temperature (98.6°F), Freezing point (32°F)
True or false: the outer extremities, such as the hands, are not a body temperature.
True
How many microns is equal to 1.6 inches of water column on a manometer?
3,000 microns
What is the definition of calibration?
To change the instruments out-put/reading to correspond to a standard or correct reading.
Why are most glass thermometers not able to be calibrated?
Because the graduations are etched on the stem.
Accuracy is more important in high or low temperatures?
Low temperatures.
A 100 ohms resistor that has a 10% tolerance will measure between __ ohms and ___ ohms.
- 90 ohms
- 110 ohms
The electric resistance of a heater will be ______ when they get hot.
Changed.
How often should combustion analyzers be calibrated?
Annually.
The potassium hydroxide in the wet kit should be changed after roughly how many tests?
Roughly after 200 test (according to manufacture’s guidelines).
How often should a volt meter be checked against a high quality bench meter?
Once a year.
If the temperature sensing instrument is to be used more than 1000ft above sea level, use a _____ thermometer as a standard instead of the boiling water temperature.
Laboratory Glass
What is a good investment for use in calibrating electronic thermometers?
A laboratory-grade glass thermometer.
It is impossible to determine a correct gauge reading if the gauge is not set at ___ at the start of the test.
0
Ice made from what type of water is preferred for performing a low temperature check?
Purified or distilled water.
True or false: The thermometer indicates the temperature of the sensing element, not the temperature of the object or liquid.
True
What should be done to the gauge manifold and hoses prior to performing a pressure test?
Purge the gauge manifold & hoses of air.
What prevents the needle on the high side manifold gauge from backing up too far when checking a micron gauge?
Atmospheric pressure
If a meter is out of calibration, what is the first thing that should be checked?
Check the batteries and charge if necessary.
True or false: The boiling point of water is suitable for checking the thermometer in the flue gas kit even though it is near the bottom of the scale.
True.
To improve the pumping capacity of a vacuum pump, what should be done?
Change the oil
True or false: A small gauge is more accurate for monitoring systems that operate in a vacuum because the needle doesn’t have to travel far between 0 psi and 30 in. Hg.
False
How can you improve the accuracy of the temperature sensing element?
Use a reference leak canister
