User's Guide Hygro-Thermometer + InfraRed Thermometer Model RH101 Patented
Introduction Congratulations on your purchase of the Extech Hygro-Thermometer plus InfraRed Thermometer. This device measures relative humidity, air temperature (with probe), and surface temperature (with the InfraRed function). The large, easy-to-read backlit LCD includes primary and secondary displays plus numerous status indicators. The InfraRed feature includes a laser pointer for convenient targeting. Careful use of this meter will provide years of reliable service.
Meter Description 1. Humidity/Air Temperature Probe 2. Probe input jack 3. Laser pointer 4. IR Sensor 5. Rubber holster 6. LCD Display 7. IR thermometer measurement button 8. IR and Relative Humidity function buttons (4) 9. Air Temperature function buttons (3) 10. Probe holder 11. Power ON/OFF button 12.
Operation Power Press the button to turn power on or off. Probe Humidity and Temperature Measurements 1. Attach the probe to the meter via the jack at the top of the meter. 2. Hold the probe in the area to be tested & allow adequate time for readings to stabilize. 3. Read the Relative Humidity (center of LCD) and Probe Temperature (top of LCD). NOTE: Do not immerse the probe in liquid; it is intended for use in air only. InfraRed (Non-Contact) Temperature Measurements 1.
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 Cloth (black) 0.98 Asphalt 0.90 to 0.98 Human skin 0.98 Concrete 0.94 Lather 0.75 to 0.80 Cement 0.96 Charcoal (powder) 0.96 Sand 0.90 Lacquer 0.80 to 0.95 Earth 0.92 to 0.96 Lacquer (matt) 0.97 Water 0.67 Rubber (black) 0.94 Ice 0.96 to 0.98 Plastic 0.85 to 0.95 Snow 0.83 Timber 0.90 Glass 0.85 to 1.00 Paper 0.70 to 0.94 Ceramic 0.90 to 0.94 Chromium oxides 0.81 Marble 0.94 Copper Oxides 0.
Battery Replacement The battery symbol to be replaced. appears on the lower right of the LCD when the 9V battery needs Replace the 9V battery as follows: 1. Turn the meter off and disconnect the air temperature probe. 2. Remove the large flat-head screw on the rear of the meter to remove the probe holder. 3. Remove the rubber holster that surrounds the entire meter by pulling it over the top of the meter. 4. Remove the small Phillips head screw on the rear of the meter. 5.
