USER MANUAL Model 401025 Digital Light Meter Additional User Manual Translations available at www.extech.
Introduction Congratulations on your purchase of the Extech Digital Light Meter. This device is shipped fully tested and calibrated and, with proper use, will provide years of reliable service. Please visit our website (www.extech.com) to check for the latest version of this User Guide, Product Updates, and Customer Support. Meter Description 1. LCD Display 2. Data Hold Switch 3. Power Off/Range Switch 4. Analog Output Terminal 5. Battery Compartment (rear) 6.
Operation 1. Select Units (Lux or Ft-candle) and the Response Time (Fast/Slow) using the slide switch. Typical selection is Slow and Fc using the gray lettering. 2. Select the maximum range using the Range Switch. 3. Hold the Light Sensor so that the sensor faces the light source to be measured. 4. 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 (see notes below). 5.
Selecting a Measurement Range The meter has three measurement ranges for each unit of measure (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 0-5000 range.
Replacing the Battery When the left corner of the LCD display shows LO BAT the battery output is below the design limit and the battery needs to be replaced. However, reliable measurement can still be taken for several hours before the tester becomes inaccurate or switches off. 1. Open the Battery Cover at the back of the tester and remove the old battery. 2. Replace with a new 9V battery and install the cover securely. Never dispose of used batteries or rechargeable batteries in household waste.
Range Specifications Lux Range In-range Display Resolution Accuracy (FS) 2,000 Lux 0-1,999 Lux 1 Lux ± (5% + 2digits) 20,000 Lux 2,000-19,990 Lux 10 Lux ± (5 % + 2digits) 50,000 Lux 20,000-50,000 Lux 100 Lux ±(5 % + 2digits) Range In-range Display Resolution Accuracy (FS) 200 Fc 0-199.9 Fc 0.1 Fc ± (5% + 2digits) 2,000 Fc 200-1,999 Fc 1 Fc ± (5% + 2digits) 5,000 Fc 2,000-5,000 Fc 10 Fc ± (5% + 2digits) Foot-candle (Fc) Frequency Spectrum 1 0.8 0.6 0.4 0.
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 Ty