UNIT 11

Question 1

True or false: The draft gauge should only be stored in a vehicle so that it is readily available when needed.

Answer 1

False

Question 2

What are three temperature reference points for checking temperature measuring instruments?

Answer 2

Water boiling point (212°F), Body temperature (98.6°F), Freezing point (32°F)

Question 3

True or false: the outer extremities, such as the hands, are not a body temperature.

Answer 3

True

Question 4

How many microns is equal to 1.6 inches of water column on a manometer?

Answer 4

3,000 microns

Question 5

What is the definition of calibration?

Answer 5

To change the instruments out-put/reading to correspond to a standard or correct reading.

Question 6

Why are most glass thermometers not able to be calibrated?

Answer 6

Because the graduations are etched on the stem.

Question 7

Accuracy is more important in high or low temperatures?

Answer 7

Low temperatures.

Question 8

A 100 ohms resistor that has a 10% tolerance will measure between __ ohms and ___ ohms.

Answer 8

1. 90 ohms
2. 110 ohms

Question 9

The electric resistance of a heater will be ______ when they get hot.

Answer 9

Changed.

Question 10

How often should combustion analyzers be calibrated?

Answer 10

Annually.

Question 11

The potassium hydroxide in the wet kit should be changed after roughly how many tests?

Answer 11

Roughly after 200 test (according to manufacture’s guidelines).

Question 12

How often should a volt meter be checked against a high quality bench meter?

Answer 12

Once a year.

Question 13

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.

Answer 13

Laboratory Glass

Question 14

What is a good investment for use in calibrating electronic thermometers?

Answer 14

A laboratory-grade glass thermometer.

Question 15

It is impossible to determine a correct gauge reading if the gauge is not set at ___ at the start of the test.

Answer 15

0

Question 16

Ice made from what type of water is preferred for performing a low temperature check?

Answer 16

Purified or distilled water.

Question 17

True or false: The thermometer indicates the temperature of the sensing element, not the temperature of the object or liquid.

Answer 17

True

Question 18

What should be done to the gauge manifold and hoses prior to performing a pressure test?

Answer 18

Purge the gauge manifold & hoses of air.

Question 19

What prevents the needle on the high side manifold gauge from backing up too far when checking a micron gauge?

Answer 19

Atmospheric pressure

Question 20

If a meter is out of calibration, what is the first thing that should be checked?

Answer 20

Check the batteries and charge if necessary.

Question 21

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.

Answer 21

True.

Question 22

To improve the pumping capacity of a vacuum pump, what should be done?

Answer 22

Change the oil

Question 23

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.

Answer 23

False

Question 24

How can you improve the accuracy of the temperature sensing element?

Answer 24

Use a reference leak canister

Question 25

In order to check both manifold gauges at the same time, which hose is connected to the refrigerant cylinder?

Answer 25

The center hose

Question 26

** EXTRA CREDIT**
How is the meter being checked against the bench meter in Fig 11.20 connected to the bench voltmeter?

A. Series
B. Parallel
C. Series parallel
D. None of the above

Answer 26

Series