Chapter 11 Flashcards
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
32°F (ice & water)
98.6°F (body temp)
212°F (boiling point)
The outer extremities, such as hands, are not a body temperature
True
What is the def of calibration
Changing the instruments output/reading to correspond with the standard/correct reading
Why are most glass thermometers not able to be calibrated
Because the graduations are etched on the stem
Is accuracy more important in high or low temps
Lower temps
The electric resistance of a heater will be ____ when they get hot
Greater
How often should combustion analyzers be calibrated?
Annually, wet kit doesn’t need to be calibrated
The potassium hydroxide in the wet kit should be changed after roughly how many tests.
After 200 tests
How often should a volt meter be checked against a high quality bench meter?
At least once a year or whenever you suspect the readings are off.
If the temperatures sensing instrument is to be used more than a 1000 feet 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?
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
T/F
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 and hoses of air
What prevents the needle on the high side manifold gauge from backing up too far when checking a micron gauge.
Little peg
If a meter is out of calibration, what is the first thing that should be checked?
Check the batteries and change if necessary.
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 or false)
True
To improve the pumping capacity of a vacuum pump, what should be done?
Change the oil
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 psig and 30 in. Hg. (True or False)
False
How can you improve the accuracy of the temperature sensing element?
Temp leads wrapping the temp sensing element will insulate it from the surrounding air, giving more accurate reading.
In order to check both manifold gages at the same time, which hose is connected to the refrigerant cylinder?
Center hose
