Hygrometers (Figure 1-36) are used to measure the relative humidity in a controlled space. Hygrometers are also commonly called relative humidity meters. See Item 16…

Psychrometrics is the study of air and its properties, including temperature, pressure, moisture, and other characteristics. Control o f these properties is essential for human…

Velometers (Figure 1-32) are used to measure the velocity of airflow. Like the anemometers described previously, velometers are used when evaluating the operation and/or balancing…

Anemometers are used to measure the velocity of airflow. Measurement of air velocity must be performed when evaluating the total operation of an air distribution…

The hermetic compressor analyzer (Figure 1-28) is a single test instrument used to make multiple tests on hermetic compressors. This device eliminates the need for…

The capacitor tester (Figure 1-27) is used to test capacitors to determine their specific capacitance value and to find out if they are good, open,…

The volt-ohm-milliammeter (YOM) is also called a multimeter. The multimeter is used for all phases of service work including installation, preventive maintenance, and troubleshooting. The…

The alternating current (AC) clamp-on ammeter is used to measure the total AC current being drawn by a system or by the individual loads in…