INSTRUCTION MANUAL Model 445703 Big Digit Hygro-Thermometer • Displays temperature and relative humidity • Selectable temperature units oC/oF • MIN/MAX memory and recall • For wall-mount or desktop use 1. INTRODUCTION Congratulations on your purchase of Extech’s Big Digit Hygro-Thermometer. This professional meter, with proper care, will provide years of safe reliable service. 2. SPECIFICATIONS Accuracy Range Temperature o -10 to 60 C o 14 to 140 F o o o + 1.0 C within -10 C to 50 C o o o + 1.8 F within 14 F to 122 F Battery + 5% RH within 25% to 85% RH and o o 0 to 50 C or 32 to 122 F One (1) 1.5V 'AAA' cell Size / Weight 4.3 x 3.9 x 0.78” (109 x 99 x 20mm) / 6 oz. (169g) Humidity 10% to 99% 1 445703 Ver. 1.7 07/05 3. OPERATION 1. Open the battery compartment by pushing the cover on the rear of the instrument downward as indicated by the arrow. Remove the battery safety strip and the protective cover on the LCD display. The instrument is now ready for use. 2. The temperature units can be selected via the switch located on the rear of the instrument. 3. The upper display indicates the temperature in degrees C or F. The lower display indicates relative humidity in %. 4. Displaying the minimum and maximum values. a. Press the MAX/MIN button. The highest value measured since the Reset button was last pressed appears on the display. b. Press the MAX/MIN button again to display the lowest value measured since the Reset button was last pressed. c. Press the MAX/MIN button again to return to normal display operation. 5. Resetting (clearing) the MAX/MIN memory. a. Press and hold the RESET button for 1 second while in the MAX/MIN display mode to clear the memory and start recording new max/min values. 6. The unit can be wall-mounted or placed on a flat surface using the fold-out footing. 7. The low battery flag will appear on the display when the battery voltage is low. Replace the battery when this occurs. 4. BATTERY REPLACEMENT 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’ battery and replace the cover. 5. CALIBRATION / REPAIR SERVICES Extech offers repair and calibration services for the products we sell. Extech also provides NIST certification for most products. Call the Customer Service Department for information on calibration services available for this product. Extech recommends that annual calibrations be performed to verify meter performance and accuracy. 6. WARRANTY EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210 for authorization or visit our website www.extech.com for contact information. A Return Authorization (RA) number must be issued before any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental or consequential damages. Extech's total liability is limited to repair or replacement of the product. The warranty set forth above is inclusive and no other warranty, whether written or oral, is expressed or implied. Copyright © 2005 Extech Instruments Corporation. All rights reserved including the right of reproduction in whole or in part in any form. 2 445703 Ver. 1.7 07/05