User Guide Heavy Duty Psychrometer + IR Thermometer Model HD500
Introduction Congratulations on your purchase of the Extech HD500 Psychrometer. This handheld meter measures and displays Air Temperature, Relative Humidity, Dew Point, Wet Bulb and also Surface Temperature using the built-in IR thermometer. This meter is shipped fully tested and calibrated and, with proper use, will provide years of reliable service. Features • Triple digital LCD display. • Fast response, all data is calculated four times per second.
Meter Description 1. Humidity & Air Temperature Sensor 2. Type K Thermocouple input jack 3. Laser pointer beam 4. IR temperature sensor 5. USB Interface 6. LCD Display 7. Upper display HOLD button 8. Upper display Temp./Wet Bulb/Dew Point button 9. Upper display record Max/Min button 10. IR Measurement button 11. °F/°C units button 12. Lower display HOLD button 13. Lower display record Max/Min button 14. Backlight button 15.
Operation Basic Measurements 1. Press the button to turn power on. 2. The upper display will indicate Air Temperature, Wet Bulb Temperature or Dew Point Temperature and % Relative Humidity. Press the WB/DP button to toggle between Air, WB or DP. 3. The lower display will indicate Type K temperature or IR Temperature. Press and hold the IRT button to select the IR Thermometer. The TYPE-K function will display “-------“ if a type k probe is not inserted into the meter. 4.
MIN-MAX Recording Mode 1. Press the MAX/MIN button (one for upper display and one for lower display) to begin recording the Maximum and Minimum reading. The REC MAX icon will appear and only the maximum value measured will appear in the display. The display will update only if a value higher than the currently displayed value is measured. 2. Press the MAX/MIN button again to display the minimum values. The REC MIN icon will appear and only the minimum recorded value will appear in the display. 3.
InfraRed Measurement Considerations • When taking IR measurements the meter automatically compensates for ambient temperature changes. Note that it may take up to 30 minutes to adjust to extremely wide ambient changes. • Low temperature measurements quickly followed by high temperature measurements may require several minutes to stabilize as a result of the IR sensor cooling process. • If the surface of the object under test is covered with frost, oil, grime, etc., clean before taking measurements.
Thermal Emissivity Table for Common Materials Material Emissivity Material Emissivity Asphalt 0.90 to 0.98 Cloth (black) 0.98 Concrete 0.94 Human skin 0.98 Cement 0.96 Leather 0.75 to 0.80 Sand 0.90 Charcoal (powder) 0.96 Earth 0.92 to 0.96 Lacquer 0.80 to 0.95 Water 0.67 Lacquer (matt) 0.97 Ice 0.96 to 0.98 Rubber (black) 0.94 Snow 0.83 Plastic 0.85 to 0.95 Glass 0.85 to 1.00 Timber 0.90 Ceramic 0.90 to 0.94 Paper 0.70 to 0.94 Marble 0.94 Chromium oxides 0.
Specifications General Specifications Display Dual Display Multi-function LCD with 9999 counts Data Hold Freezes displayed reading Sampling rate 1 reading per second Sensors Relative Humidity: Capacitance, Air Temp: Thermistor IR Distance to Spot ratio 30:1 IR Spectral response 6 to 14µm IR Emissivity 0.
