Unit 11

Question 1

T/F
The draft gauge should only be stored in a vehicle so that is is readily available when needed

Answer 1

False. Only when needed as it can be damaged in transportation

Question 2

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

Answer 2

1. 32 F (ice and water)
2. 212 F (boiling water)
3. 98.6 F (body temp)

Question 3

T/F
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

3000 microns

Question 5

What is the definition of calibration?

Answer 5

Changing the instruments output or reading to correspond to a standard of correct reading

Question 6

Why are most glass thermometers not able to be calibrated?

Answer 6

Their graduations are etched into the stem

Question 7

Accuracy is more important in high or low temperatures?

Answer 7

Lower temps. This can translate to larger % errors

Question 8

A 100 ohm resistor that has a 10% tolerance will measure between _______ and _____ ohms?

Answer 8

90 - 110 ohms

Question 9

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

Answer 9

Greater

Question 10

How often should combustion analyzers be calibrated?

Answer 10

Wet kits do not need to be calibrated. Electronic analyzers should be calibrated annually.

Question 11

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

Answer 11

Roughly 200 tests

Question 12

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

Answer 12

Periodically roughly 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

Laboratory grade glass thermometer

Question 15

It is impossible to determine a correct gauge reading if the gauge is not set to _____ 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

distilled or purified water

Question 17

T/F
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

Open the gauge to atmosphere and check that both gauges read 0 psig

Question 19

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

Answer 19

The high side “bottoms” out at 0 Psig and does not register vacuum. There is also a peg.

Question 20

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

Answer 20

Batteries. Then leads that could become frayed

Question 21

T/F
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

T/F
A small gauge is more accurate for monitoring systems that operate in vacuum because the needle doesn’t have to travel far between 0 psig and 30 inHg

Answer 23

False. Large gauges are more accurate because the needle moves farther from 0 to 30 in Hg.

Question 24

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

Answer 24

Insulate and insure good contact. This will prevent surrounding air from skewing readings

Question 25

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

Answer 25

center yellow hose

Question 26

How is the meter being checked against the bench meter in Fig. 11.20 connected to the bench voltmeter?

Answer 26

Parallel