# Energy Efficiency Reference/Refrigeration/Data Collection/Standard Refrigeration Data Collection Tools
## Standard Refrigeration Data Collection Tools

* Digital Multimeter(DMM): Power used by an electric motor can be calculated from measurements of voltage and current. Use a DMM to measure voltage at the motor starter box. The DMM can measure line-to-line or line-to-ground voltage, depending on probe placement. Refer to appropriate safety publications and use caution when measuring high voltage.
* Clamp-on Ammeter: Current is also needed to calculate power. A clamp-on ammeter senses line current by measuring the current induced in the ammeter by the magnetic field from current being measured. Use the clamp-on ammeter to measure current in all three phases for power calculations. It is important to measure current at as many operating conditions as possible and to accurately mode equipment operation.
* Recording Power Meter (PM): Use a recording power meter to measure and store power profiles over time. A power meter (PM) has three CT's. three voltage probes, a neutral, and a ground probe. Connect these to the motor leads to calculate power used by an electrical load. Read the instructions carefully before connecting the PM to ensure proper installation based on the type of power system (delta or Y, 3 or 4 wire). Recording intervals are also important to capture the operating characteristics. Shorter intervals are important for rapidly changing power profiles, but generate more data and use recorder storage capacity faster.
* Sling Psychrometer: Use a sling psychrometer to measure wet and dry-bulb air temperatures. The wet-bulb thermometer has a damp sleeve around the bulb. Spin the psychrometer through the air on its cord,, chain , or pivot. water evaporates from the wet sleeve causing a cooling effect until the bulb reaches equilibrium at the wet bulb temperature. The wet-bulb temperature will be less than the dry psychrometric charts to determine other air properties based on wet and dry bulb temperatures, such as relative and absolute humidities, and dew point. Digital psychrometers are also available.
* Digital Thermometer: Digital thermometers are faster, more accurate over a larger range, and easier o read than analog ones. Probes are often specialized for different environments such as measuring temperatures at a solid surface, in liquids, and in air. Sensor types include thermocouples, thermistors, RTD, and infrared.
* Hot-Wire Anemometer: This instrument calculates airflow rates by measuring convection related heat loss resulting from air passing by a hot wire. It can be used to analyze fans. A whole section could be devoted to this instrument. Other types of airflow meters include rotameters, rotating vanes, pitot tubes, and vortex shedding meters.
* Stopwatch: Use watches to measure equipment cycle times. They are also used to measure the time it takes to fill a known volume from which water flow rates can be calculated.
* Light Meter:
Measure lighting levels when recommending efficient replacement lights for a refrigerated space. Measure lighting levels in several locations through the space and average.
Miscellaneous Items
* Rag used to wipe off dirty motor nameplates
* High-voltage gloves, hard hats, glasses and ear plugs used for safety
* Tape measure, screwdriver, and pliers to take measurements, adjust switches, and open panels.
* A flashlight is helpful because refrigeration equipment is often in areas with low light levels