User's Guide Heavy Duty Digital Light Meter with PC Interface Model HD400
Introduction Congratulations on your purchase of the Extech HD400 Digital Light Meter. The HD400 measures illuminance in Lux and Foot candles (Fc). The HD400 includes a PC interface TM and Windows compatible software for real-time monitoring and storage of light level data. This meter is shipped fully tested and calibrated and, with proper use, will provide years of reliable service.
Description Meter Description 1. Sensor cable plug shown connected to meter jack 2. USB jack for PC interface (under the flip-down cover) 3. LCD Display 4. Upper Push Button set 5. Lower Push Button set 6. Sensor’s light collector dome 7. Sensor housing (protective cover not shown) 8. Power ON-OFF button 1 2 3 4 5 8 NOTE: The battery compartment, tripod mount, and tilt stand are located on the rear of the instrument and are not pictured 6 7 Display Description 1.
Operation Meter Power 1. Press the Power button 2. If the meter does not switch on when the power button is pressed or if the low battery icon is displayed on the LCD, replace the 9V battery to turn the meter ON or OFF Auto Power Off (APO) 1. The meter is equipped with an automatic power off (APO) feature that turns the meter off after 20 minutes of inactivity 2. To defeat the APO feature, press and hold the APO button.
Maximum (MAX) and Minimum (MIN) Reading Memory The MAX-MIN function allows the meter to store the highest (MAX) and lowest (MIN) readings. 1. Press the MAX-MIN button to activate the feature. ‘MANU MAX’ will appear on the top of the display and the meter will only display the highest reading encountered. 2. Press the MAX-MIN button again. ‘MANU MIN’ will appear on the top of the display and the meter will only display the lowest reading encountered. 3.
USB PC Interface Description The HD400 meter can be connected to a PC via its USB interface. A USB cable, along with TM Windows software, is included with the meter. The software allows the user to view, store, and print readings from the PC. Note that the HD400 does not datalog readings, meaning that it does not store readings in an internal memory; it simply displays readings on the PC as they are taken in real-time; after which the readings can be analyzed, stored as text, or printed.
Specifications Range Specifications Units Range Resolution Lux 400.0 0.1 4000 1 40.00k 0.01k 400.0k 0.1k 40.00 0.01 400.0 0.1 Foot candles 4000 1 40.00k 0.01k Accuracy ± (5% rdg + 10 digits) ± (10% rdg + 10 digits) ± (5% rdg + 10 digits) ± (10% rdg + 10 digits) Notes: 1. Sensor Calibrated to standard incandescent lamp (color temperature: 2856K) 2. 1Fc = 10.
Maintenance Cleaning The meter and its sensor can be cleaned with a damp cloth. A mild detergent may be used but avoid solvents, abrasives, and harsh chemicals. Battery Installation / Replacement The battery compartment is located on the back of the meter. The compartment is easily accessed by pressing and sliding the rear battery compartment cover off of the meter in the direction of the molded arrow.
