User’s Guide Model 445814 Hunidity Alert MAX A L E R T Humidity Alert Temperature MAX Humidity Indicator with Dew Point and Programmable Hi/Lo %RH Alarms A L E R T DEW Point MAX CC 445814 MAX/MIN Humidity Alarm RESET Introduction Operation Calibration Congratulations on your purchase of Extech’s Humidity Alert Hygro-Thermometer. Humidity alarms warn when the %RH exceeds a pre-set HI or LO limit. It also features Humidity and Temperature calibration adjustments. The unit can be wallmounted or placed on a flat surface using the fold-out stand. This professional meter, with proper care, will provide years of safe reliable service. Preparation for use Open the battery compartment by pushing the cover on the rear of the instrument downward as indicated by the arrow. Remove the battery insulating strip and the protective film cover on the LCD display. Temperature Units Select ºF or ºC units using the rear selection switch. Audible alarm Select or using the rear selection switch to turn the audible alarm on or off. Maximum / Minimum display 1. Press the MAX/MIN button. The highest value measured since the Reset button was last pressed appears on the display. 2. Press the MAX/MIN button again to display the lowest value measured since the Reset button was last pressed. 3. Press the MAX/MIN button again to return to normal display operation. Resetting (clearing) the MAX/MIN memory 1. Press the MAX/MIN button to enter the MAX/MIN mode. 2. Press and hold the RESET button for 1 second to clear the memory and start recording new max/min values. Setting the %RH Alarm Limits 1. Simultaneously Press and HOLD the MAX/MIN and RESET button until “HI” and the stored HI %RH limit appears flashing. 2. Press the RESET button to set the Hi %RH limit. Hold the button in for rapid adjustment. 3. Press the Max/Min button. “LO” and the stored LO %RH limit will appear flashing 4. Press the RESET button to set the LO %RH limit. 5. Press the Max/Min button to turn on or off the alarm. The will appear in the display when the alarm is alarm icon active. 6. Press and hold the RESET button to save the settings and exit the mode. Alert If %RH exceeds the HI limit or goes below the LO limit the alert will be activated. The alert consist of two flashing ‘ALERT” icons in the upper display, a flashing red light and an audible buzzer (for 60 seconds) RH Calibration 1. Insert the meter into a humidity chamber. The reference should be >70% RH. 2. Check the reading after 1 hour. 3. Adjust the RH calibration pot in ½ turn increments, waiting for the display to update after each adjustment, until the reading is within the accuracy specification. Meter Description 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. Temperature-Humidity Sensor %RH Display Dew Point Display Temperature Display %RH LED alarm 4 Max/Min push button 5 Reset push button Audible Alarm ON/Off switch Tilt Stand Humidity calibration adjust Temperature units switch (ºF/ºC) Temperature calibration adjust Wall hanger 9 Battery compartment 10 1 Hunidity Alert MAX A L E R T Temperature MAX A L E R T 2 DEW Point MAX 3 445814 MAX/MIN Humidity Alarm 8 11 Al. On Al. Off RESET 6 7 13 O C O F 14 12 Battery Replacement The low battery flag will appear on the display when the battery voltage is low. Replace the battery when this occurs. Open the battery compartment by sliding the battery cover on the rear of the instrument downward as indicated by the arrow. Replace the 1.5V ‘AAA’ batteries and replace the cover. Temperature Calibration 1. Place the meter in a stabilized environment of approximately 21°C. 2. Check the reading after 1 hour. 3. Adjust the temperature calibration pot in ½ turn increments, waiting for the display to update after each adjustment, until the reading is within the accuracy specification. Specifications Range o Temperature -10 to 60 C o 14 to 140 F Humidity 10% to 99% Dew Point Battery Weight Dimensions o Accuracy o o o + 1.0 C within -10 C to 50 C o o o + 1.8 F within 14 F to 122 F + 4% RH within 25% to 85% RH o o and 0 to 50 C or 32 to 122 F o o +/-2 C. @ 20 C o o +/-3.6 F @ 68 F -36 to 60 C o -32.8 to 140 F (2) 1.5V 'AAA' cell 6 oz (169g) Display: 4.3x3.9x0.8” (109x99x20mm) Note: If subjected to an electrostatic discharge the meter may malfunction and require the user to perform a reset. Copyright © 2009 Extech Instruments Corporation. All rights reserved including the right of reproduction in whole or in part in any form. www.extech.com V3.2 5/09