Energy Audit Instruments And Their Uses

1. Voltmeter and ammeter to measure voltage and current.
2. Power factormeter to measure power factor.
3. Power Analyser : An online power analyser gives a continuous measurement and record of real power ( kVA), apparent power (kVA), voltage, current and power factor.
4. Multimeter
5. Synergy meter : This instrument measures and records current, voltage, power factor, frequency, kWh, and KVAh.

 Lighting Measurements

• Usually, a substantial portion of electrical energy requirement of a plant are for illumination.
• A lux meter is a very convenient instrument to measure the level of illumination.

Chemical Measurements

• A flue gas analysis is an essential part of energy audit in a plant emitting flue gases.
• The instruments used for flue gas analysis are :

1. Dragger : It indicates the degree of combustion in a boiler especially the extent of carbon monoxide (CO) in flue gases.
2. Fyrite kit : This kit is used to measure percentage of Co₂ and O₂ in the flue gases.

 Mechanical Instruments

1. Flow : The instrument for flow measurement are anemometer (to measure air velocity and flow in a duct). Pitot tube (to measure pressure and gas flow rate in big ducts and chimneys), electronic air flow meter (to measure velocity and pressure of air), heated thermocouple anemometer (to measure air velocity in ducts), impact tube (to measure high air velocity in small tubes) and smoke pellet (to measure low air velocity in a room).
2. Pressure : The instruments used for pressure measurements are : absolute pressure manometer  (for low absolute pressure), diaphragm guage (for low absolute pressure), barometer (for atmospheric pressure), manometer (for medium pressure differential), micromanometer (for very low pressure differential), Draft guage (for low pressure differential). Bourdon tube (for medium and high pressure differential and pressure transducer (for remote measurement of rapidly changing pressure). Many guages available now-a-days have digital display.
3. Speed : Non-contact tachometer and contact tachometer.
4. Steam trap testing : Engineers stethoscope and electronic steam tester.
5. Leaks : Ultrasonic leak checker. It operates by generation of ultrasonic waves and is used to check compressed air and gas leakage.

Humidity Measurements

The instruments available for humidity measurement are Psychrometer (similar to dry and wet bulb thermometer) dew point hygrometer, electrical conductivity humidity meter, electrolytic hygrometer.

1. Glass stem thermometer : Mercury in glass, alcohol in glass are used for temperature measurement of gas air and liquids in the range of 20 to 500°C. 
2. Thermocouple transducers : They are used for measurement of surface temperature, material temperature , air and gas temperature. They are available in seven types (for various thermocouple metal combinations) for temperature range of – 270°C to 182°C.
3. Resistance thermometer (platinum resistance , nickle resistance, thermistor) suitable for labour 150°C to 1000ºC but costly than other thermometers.
4. Bimetallic transducer (0 to 500°C). Their accuracy is poor.
5. Optical pyrometers (for above 750°).
6. Radiation pyrometers : Very accurate but costly, suitable for very high temperatures.