Bench-top apparatus that illustrates the principles of humidity measurement and compares various methods of measurement.
• Demonstrates how to measure and calculate the relative humidity (moisture content) of air
• Allows students to compare diff erent humidity measuring instruments
• Includes air fi lter to help prevent dust and other impurities from entering instruments
• Includes mechanical and electronic instruments to measure temperature and humidity
• Variable fl ow-rate fan to show the eff ect of air fl ow on humidity measurement
• Compact unit for ease of use and storage
The Humidity Measurement unit allows students to compare diff erent methods of humidity measurement. It shows the diff erences in accuracy between instruments and their ease of use. It also includes a blower unit with a valve to show how air flow aff ects the diff erent instruments.
A square cross-section duct supports a blower unit. The duct contains a selection of instruments to measure humidity and temperature. A clear window in the duct allows students to see the instruments. A removeable outlet grill gives access to the instruments. A fan in the blower unit above the duct supplies a fl ow of air and a hand-operated valve varies the air fl ow rate. This allows students to study the eff ect of air fl ow on the instruments. An orifi ce plate and manometer measure the fl ow rate. An air fi lter in the air fl ow path stops dirt or other particles aff ecting the instruments. The instruments include a whirling hygrometer that students use near the outlet of the duct, providing an extra method of measuring temperature and humidity.
The back of the duct includes an extra port. It allows students to introduce low-pressure steam into the duct, to increase the range of experiments (steam generator not included).
• Measurement of air fl ow rate in a duct
• Measurement of relative humidity using diff erent types of instrumentation
• Comparison of measurement methods for accuracy and ease of use