Deck 11: Calibrating Instruments

Question 1

If the ammeter is off by more than _____%, it should be sent to the repair shop.

A) 1
B) 2
C) 5
D) 10

Answer 1

D

Question 2

To check the temperature leads of an electronic thermometer for high temperature, they should be ____.

A) placed on the bottom of a pan of boiling water
B) suspended in a pan of boiling water
C) suspended in the vapor above a pan of boiling water
D) suspended in a pan of boiling water located at least 1,000 ft. above sea level

Answer 2

B

Question 3

Stirring the ice and water with the thermometer will increase the accuracy of the thermometer reading.

Answer 3

True

Question 4

To check the temperature leads of an electronic thermometer for low temperature, they should be stirred in a container of ____.

A) crushed ice and water with 1/2 teaspoon of salt added
B) crushed ice and water with 1/2 teaspoon of sugar added
C) crushed ice and pure water
D) cube ice and pure water

Question 5

Flue-gas analysis instruments analyze products of combustion from fossil-fuel-burning equipment, such as oil and gas furnaces and ____.

A) boilers
B) CO₂ testers
C) cooling towers
D) refrigerators

Question 6

Three reference points for checking temperature measuring instruments are ____.

A) 0°F, 100°F, 110°F
B) -460°F, 0°F, 32°F
C) 32°F, 98.6°F, 212°F
D) 32°F, 100°F, 250°F

Question 7

The ____ is used most frequently for amperage checks.

A) hot-wire ammeter
B) integrated ammeter
C) clamp-on ammeter
D) alternating ammeter

Question 8

____ can detect leak rates of about 1/4 oz per year.

A) Halide torches
B) Compressed air canisters
C) Electronic leak detectors
D) Mechanical leak detectors

Question 9

A device commonly used for detecting refrigerant leaks is a(n) ____.

A) compressed air canister
B) halide torch
C) water pump
D) None of the above.

Question 10

Special thermometers are used to measure temperatures above ____________________ ºF .

Question 11

____________________ thermometers are simple, economical, and accurate.

Question 12

The accuracy of a thermometer is more important when working on high temperature refrigeration (air conditioning) systems.

Question 13

It is important to note that Ohm's law, as written, will hold for AC-powered circuits that are used to operate resistive-type loads .

Question 14

____________________ means the changing of the instrument's output or reading to correspond to a standard or correct reading.

Question 15

Ohm's law is represented with the formula: ____.

A) I = R/E
B) I = E/R
C) E = R/I
D) R = I/E

Question 16

You should not spray pure refrigerant into the sensing element of a leak detector.

Question 17

Water boils at 220°F at sea level under standard atmospheric conditions .

Question 18

Some instruments cannot be calibrated.

Question 19

____________________ instruments measure the temperature of vapors, liquids, and solids.

Question 20

Refrigeration technicians must have thermometers that are accurate from 40°F to 150°F to measure the refrigerant lines and the inside of coolers.

Question 21

Why is it necessary to check the calibration of a gauge manifold periodically?

Question 22

How is the milliamp scale on a meter checked?

Question 23

Any instrument with a digital readout will have ____________________.

Question 24

Why should the thermometer element not touch the bottom of the pan when checking it in boiling water?

Question 25

How can the ohmmeter feature of a VOM meter be checked?

Question 26

____________________ instruments register pressures above and below atmospheric pressure.

Question 27

When is it important to purchase a good quality instrument?

Question 28

How can a technician determine if a temperature sensing lead of his digital thermometer is working correctly?

Question 29

What is the easiest way to check the voltage scale of a VOM meter?

Question 30

Heating and air-conditioning technicians must measure air temperatures from 40ºF to ____________________ºF.

Question 31

____________________ points for all instruments should be established to give the technician confidence.

Question 32

How can you check the clamp-on ammeter?

Question 33

What thermometer has replaced the glass-stem thermometer?

Question 34

The three easily accessible reference points for ____________________-measuring instruments are ice, body temperature, boiling water.