User's Manual Model 401025 Digital Light Meter Introduction Congratulations on your purchase of Extech’s Digital Light Meter. This professional meter, with proper care, will provide years of safe reliable service. Meter Description 1. LCD Display 2. Data Hold Switch 3. Power Off/Range Switch 4. Analog Output Terminal 5. Battery Compartment (rear) 6. LUX/Fc Switch & Response Switch 7. Light Sensor 8. Zero adjust 1 2 3 6 4 7 8 5 Operation 1. 2. 3. 4. 5. Select Units (Lux or Ft-candle) and Response Time (Fast or Slow) on the slide switch. Typical selection is Slow and Fc using the gray lettering. Select the maximum range on the "Range Switch" Hold the "Light Sensor" so that the sensor faces the light source to be measured. The Display will indicate measured values. Use a range display multiplier if on the Lux 20,000 and 50,000 ranges or on the Fc 5000 range. To "hold" a measurement, slide the "Data Hold Switch" to the "hold" position. The reading will "freeze" in the display until the "Data Hold Switch" is released. Note 1: An Over Range indication is a display of "I ". If this occurs, switch to a higher range. Note 2: For measurements made on the Fc 5000 range, the displayed reading must be multiplied by 10. Note 3: For measurements made on the Lux 20000 or 50000 range, the displayed reading must be multiplied by 10 and 100 respectively. Note 4: The meter will indicate values above the maximum ranges. The accuracy of these measurements is unknown. Range Display Multipliers Range Units Multiplier 200 Fc Direct reading 2000 Fc & Lux Direct reading 5000 Fc Reading x10 20,000 Lux Reading x10 50,000 Lux Reading x100 Lux Example: If a measurement on the 5000 Fc range displays 350, then the actual measured value is; 350 X 10 = 3500 Fc. 2 401025-EU-EN-V2.3 7/12 Selecting a Measurement Range The meter has three measurement ranges (0-200, 0-2000, and 0-5000 Fc) and (0-2000, 0-20000, and 0-50000) Lux). The proper range selection will produce the most accurate reading. Always select the range that produces the maximum number of digits without exceeding the maximum count for that particular range. For example, a reading of 1456 Fc should be read on the 0 - 2000 range, not the 05000 range. Zero procedure The meter zero (display with no light input) may change with time. Occasional checking and adjustment may be required. 1. Completely cover the sensor to block out any light. 2. Set the range switch to the lowest Lux or Fc range 3. Using a small screwdriver, adjust the “Zero” control for a zero display. The last digit may change slightly. This is normal and does not affect the accuracy of the meter. Analog Output The analog output jacks on the front panel produce a 0.1mV DC per digit signal that can be used for recording or datalogging purposes. Lighting Type Correction Factors O The 401025 light meter is calibrated under a precise "Standard tungsten light source of 2856 K". If the meter is to be used under a different type of light the correction factor of from the table below should be applied to the readings obtained. Mercury Lamp Fluorescent Lamp Daylight Sodium Metal Halide x1.14 X0.92 to 1.12 x1.00 x1.22 x1.00 Replacing the Battery When the left corner of the LCD display shows "LO BAT", it indicates the battery output is below the design limit and the battery needs to be replaced. However, reliable measurement can still be taken for another few hours before the tester becomes inaccurate. 1. Open the Battery Cover at the back of tester and remove the battery. 2. Replace with a 9V battery and install the cover. You, as the end user, are legally bound (EU Battery ordinance) to return all used batteries, disposal in the household garbage is prohibited! You can hand over your used batteries / accumulators at collection points in your community or wherever batteries / accumulators are sold! Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the end of its lifecycle 3 401025-EU-EN-V2.3 7/12 Specifications General Specifications Display Measurement Ranges Sensor Zero Adj. Sampling Time Response Time Over input indication Analog Output Operating Temperature Operating Humidity Power Supply Power Current Weight Dimension Optional Accessories Range Specifications Lux Range 2,000 Lux 20,000 Lux 50,000 Lux Foot-candle (Fc) Range 200 Fc 2,000 Fc 5,000 Fc 13 mm (0.5") LCD (Liquid Crystal Display). Lux, Ft-candle (Fc). Lux: 0 to 50,000 Lux, 3 ranges. Foot-candle: 0-5,000 Fc, 3 ranges. Exclusive photo diode & color correction filter, spectrum designed to meet C. I. E. Manual adjustment. Approx. 0.4 sec. Fast: 0.25s; Slow: 1s Indication of "1 " 0.1 mV/1 digit, max. output :200mV. O O O O 0 C to 50 C (32 F to 122 F) Less than 80% RH. 006P DC 9V battery Approx. 2 mA DC 220 g / 0.52 LB Main instrument: 163x70x30mm (6.4x2.8x1.2 inch). Sensor Probe: 85x55x12 mm (3.2x2.2x0.5 inch). Vinyl pouch carrying case, 409996 In-range Display 0-1,999 Lux 2,000-19,990 Lux 20,000-50,000 Lux Resolution 1 Lux 10 Lux 100 Lux Accuracy (FS) ± (5% + 2digits) ± (5 % + 2digits) ±- (5 % + 2digits) In-range Display 0-199.9 Fc 200-1,999 Fc 2,000-5,000 Fc Resolution 0.1 Fc 1 Fc 10 Fc Accuracy (FS) ± (5% + 2digits) ± (5% + 2digits) ± (5% + 2digits) Frequency Spectrum 1 0.8 0.6 0.4 0.2 0 300 400 500 600 700 800 Wavelength (nm) 4 401025-EU-EN-V2.3 7/12 Appendix A: Typical Light Levels Lux Foot Candles 20-75 2-7 75-150 7-15 Factories Emergency Stairs, Warehouse Exit/Entrance Passages 150-300 15-30 300-750 30-75 750-1,500 75-150 1,5003,000 150-300 75-100 100-200 7-10 10-20 200-750 20-75 750-1,500 75-150 1,500150-2000 2,000 75-150 150-200 200-300 7-15 15-20 20-30 300-500 30-50 500-750 50-75 750-1,500 75-150 1,5003,000 150-300 Lux Foot Candles 100-150 10-15 150-200 15-20 Packing Work 200-300 20-30 Visual Work: Production Line Typesetting: Inspection Work Electronic Assembly, Drafting Office Indoor Emergency Stairs Corridor Stairs 300-500 30-50 Recreational Activities Drawing Room, Table Makeup 500-1,500 50-150 Reading, Study 1,0002,000 100-200 Sewing 75-150 150-300 7-15 15-30 Conference, Reception Room Clerical Work Typing, Drafting 300-750 30-75 750-1,500 75-150 30-75 75-100 100-150 3-7 7-10 10-15 150-200 200-750 750-1,500 15-20 20-75 75-150 Hospital Emergency Stairs Stairs Sick Room, Warehouse Waiting Room Medical Exam Room Operating Room 5,00010,000 500-1000 Eye Inspection Store Indoors Corridor/Stairs Reception Display Stand Elevator Show Window, Packing Table Storefront, Show Window Home Washing Restaurant Corridor Stairs Entrance, Wash Room Cooking/Dining Room Show Window Appendix B - Common Terms and Conversion Factors Illuminance (Visible Flux Density) 1 lm/m2 = 1 lux (lx) 10-4 lm/cm2 10-4 phot (ph) 9.290 x 10-2 lm/ft2 Luminance (Visible Flux Density per Solid Angle) 1 lm/m2/sr = Luminous Intensity (Visible Flux per Solid Angle) Luminous Flux ( Visible Flux) 1 lm/sr = 1 lumen (lm) = 9.290 x 10-2 foot-candles 1 candela/m2 1 candella 1.464 x 10-3 watts @ 555 nm Copyright © 2012 Extech Instruments Corporation (a FLIR company) All rights reserved including the right of reproduction in whole or in part in any form. www.extech.com 5 401025-EU-EN-V2.3 7/12