Changing an instrument's output or reading to correspond to a standard reading is called ________.

• referencing

• balancing

• detection

• calibration

Temperature-measuring instruments measure the temperature of _________.

• vapors only

• vapors and solids only

• vapors, solids, and liquids

• solids and liquids only

For an accurate reading, the thermometer must be __________.

• exposed to ambient air conditions for a specified period of time before use

• calibrated before every use

• checked against a pressure/temperature chart for accuracy

• in contact with the medium long enough for the sensor to become the same temperature as the medium being tested

Thermometer accuracy is more important in lower temperature ranges where small temperature differences can translate into larger percentage errors.

• True

• False

______________ can be used as reference to check the accuracy of a gauge manifold.

• Atmospheric pressure at sea level

• Crushed ice and water

• A tank of virgin refrigerant and a temperature/pressure chart

• A calibrated thermometer

When checking an ohmmeter for accuracy, resistors with a _______% tolerance are usually acceptable for the needs of an HVAC/R technician.

• 6 to 8

• 1

• 10 to 15

• 2 to 5

Ohm's Law will hold for DC-powered circuits that are used to operate inductive loads.

• True

• False

The red fluid used with some flue-gas analysis instruments is _____________.

• sodium chloride

• potassium hydroxide

• mercury

• sodium hydroxide

The two most common flue-gas analysis kits are the ___________ kits.

• electronic and combustion

• draft and temperature

• draft and electronic

• electronic and wet

When checking the accuracy of a pressure-measuring instrument, it must be checked both above and below atmospheric pressure.

• True

• False