LT300

User Guide Digital Light Meter Model LT300 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. Introduction Congratulations on your purchase of the Extech LT300 Digital Light Meter. The LT300 measures light level (illuminance) to 200,000 Lux (20,000 Fc). The LT300 offers a backlit display, MAX/MIN, Data Hold, Relative, Peak, and Reset features. This instrument is shipped fully tested and calibrated and, with proper use, will provide years of reliable service. Meter Description 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Sensor cable Analog bargraph Numerical display RANGE button ON/OFF button MAX/MIN button RESET button LCD Backlight button LUX button Fc foot candle button Protective rubber jacket RELATIVE button Data HOLD button PEAK button Photo sensor dome 1 2 15 3 4 5 6 7 11 12 13 14 8 9 10 Notes: Protective sensor cap not shown. Battery compartment, Tilt Stand, and Tripod Mount are located on the rear of the instrument. The protective rubber jacket must be removed from meter to access battery compartment. 2 LT300 V2.0 6/06 Operation Light sensor 1. The light sensor is permanently attached to the meter by the coiled cable. 2. Remove the protective cap by unsnapping it to expose the white domed light sensor. When the sensor’s protective cap is removed, the white domed light sensor lens will begin to capture light. Replace the cap when the meter is not in use. Turn Power ON or OFF Press the button to turn power on or off. If the display does not switch on, check that the 9V battery is installed and is fresh. Selecting Lux or Foot candle units of measure Press the LUX button to select lux units or the Fc button to select foot candle units. Measurement Procedure 1. Remove the protective cap from the sensor so that the white domed light sensor is exposed to the light. For overhead lighting, the sensor can be placed on a desk or table top. A tripod mount and a tilt stand are located on the rear of the meter for convenience. 2. The display will indicate the light level in Fc or Lux. 3. Press the RANGE button to select the range that provides the maximum resolution. If the ‘OL’ appears the light measurement is out of range. Select another range using the RANGE button. 4. Press the backlight button to illuminate the LCD display if needed. MAX/MIN The Max/Min function allows for recording and display of the maximum and minimum light levels over time. 1. Press the MAX/MIN button. The MAX display icon will appear and meter will now display and hold only the highest reading. The display will update only when a higher reading is measured. 2. Press MAX/MIN button. The MIN display icon will appear and meter will now display and hold only the lowest reading. The display will update only when a lower reading is measured 3. Press MAX/MIN again. The MAX MIN display icons will appear flashing and meter will now display the current reading, but will continue to record the highest and lowest values. 4. Press MAX/MIN again to cycle through MAX and MIN displays. 5. To exit the MAX MIN mode, press and hold the MAX/MIN button until the MAX and MIN icons completely disappear. Data Hold Press the HOLD button to freeze the displayed reading. The ” MANU HOLD” hold icon will appear on the display. Press the HOLD button again to return to normal operation. When the Data Hold function is enabled the analog bar graph will continue to display level changes. 3 LT300 V2.0 6/06 Peak Hold The Peak Hold feature allows the meter to captures light pulses that rise or fall down to 10µs. 1. Press and hold the PEAK button until CAL appears in the display. 2. Momentarily press the PEAK button. The ‘PMAX’ icon will appear on the LCD. The meter will then measure and display any light pulses. The display will hold the results until a higher pulse appears. 3. Press the PEAK button again to display the “PMIN” values. 4. To exit the Peak Hold mode, press and hold the PEAK button until the ‘PMAX’ or ‘PMIN’ icon disappears. Relative mode Measurements can be displayed as a difference between the measured light level and a stored reference value. To store a reading as a reference, press the REL button when the desired reference measurement is on the LCD (the REL icon will switch on). All subsequent displayed readings will be “relative” to the stored reference value. For example, if the reference value is 100 and the actual light level is 125, the meter will display 25. To view the reference value, press the REL button again so that the REL icon begins to flash. The displayed value will be the reference value. To exit the Relative mode, press and hold the REL button until the REL icon disappears. RESET Press the RESET button to clear the memory and exit from REL, HOLD, PEAK and MAX/MIN. The RESET will also reset the auto power off timer. Backlight Press the “ “ button to turn the backlight on. Press again to turn it off. Maintenance Cleaning and storage 1. The white plastic sensor dome should be cleaned with a damp cloth when necessary. Use only a mild soap if needed. Do not use solvents, abrasives, or harsh detergents to clean the dome. 2. Store the meter in an area with moderate temperature and humidity (refer to the operating and storage range in the ‘Specifications’ section). Battery Replacement When the battery power begins to fail the low battery symbol “ ”will appear on the LCD. Replace the 9V battery by first removing protective jacket that encases the meter. Remove the rear (center) battery compartment screw to access the battery compartment. Ensure that the compartment cover is securely fastened and that the protective jacket is properly installed before using the meter. 4 LT300 V2.0 6/06 Specifications Ranges and Resolution Lux 40.00, 400.0, 4000, 40.00k, 200.0kLux Foot candle (Fc) 40.00, 400.0, 4000, 20.00kFc General Specifications Display Over range indication Spectral response Spectral accuracy Temperature coefficient Sampling rate Photo detector Peak Hold Operating conditions Storage conditions Dimensions Weight Low battery indication Power supply Multi-function 3-3/4 (3999) digit LCD with Bargraph indicator LCD displays ‘OL’ CIE photopic (CIE human eye response curve) CIE V function (f1 ±0.1% per C 13.3 times per second (bargraph); 1.3 times per second (digital display) Silicon photo-diode with spectral response filter Capture light peaks to 10µS Temperature: 32 to 104 F (0 to 40 C); Humidity: < 80% RH Temperature: 14 to 140 F (-10 to 50 C); Humidity: < 80% RH 6.5 x 3.0 x 1.7" (165 x 76 x 43mm) Approx. 14.2 oz. (403g) with battery installed “ ” appears on the LCD 9V battery o o o o o Accuracy ± (5% Rdg + 0.5% Full Scale) ± (5% Rdg + 0.5% Full Scale) ï 6%) Measurement Repeatability ±2% Calibration and 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. Support line (781) 890-7440 Technical support: Extension 200; E-mail: support@extech.com Repair & Returns: Extension 210; E-mail: repair@extech.com Product specifications subject to change without notice For the latest version of this User’s Guide, Software updates, and other up-to-the-minute product information, visit our website: www.extech.com Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451 Copyright © 2006 Extech Instruments Corporation. All rights reserved including the right of reproduction in whole or in part in any form. 5 LT300 V2.0 6/06 Appendix Typical Light Levels Lux 20-75 75-150 150-300 300-750 750-1,500 1,500-3,000 75-100 100-200 200-750 Foot Candles 2-7 7-15 15-30 30-75 75-150 150-300 7-10 10-20 20-75 Factories Emergency Stairs, Warehouse Exit/Entrance Passages Packing Work Visual Work: Production Line Typesetting: Inspection Work Electronic Assembly, Drafting Office Indoor Emergency Stairs Corridor Stairs Lux 100-150 150-200 200-300 300-500 500-1,500 1,000-2,000 75-150 150-300 300-750 750-1,500 Foot Candles 10-15 15-20 20-30 30-50 50-150 100-200 7-15 15-30 30-75 75-150 Home Washing Recreational Activities Drawing Room, Table Makeup Reading, Study Sewing Restaurant Corridor Stairs Entrance, Wash Room Cooking Room, Dining Table Show Window Hospital Emergency Stairs Stairs Sick Room, Warehouse Waiting Room Medical Exam Room Operating Room Conference, Reception Room 750-1,500 75-150 Clerical Work 1,500-2,000 150-2000 Typing, Drafting Store 75-150 7-15 Indoors 150-200 15-20 Corridor/Stairs 200-300 20-30 Reception 300-500 500-750 750-1,500 1,500-3,000 30-50 50-75 75-150 150-300 Display Stand Elevator Show Window, Packing Table Storefront, Show Window 30-75 75-100 100-150 150-200 200-750 750-1,500 3-7 7-10 10-15 15-20 20-75 75-150 5,000-10,000 500-1000 Eye Inspection Spectral Sensitivity R e l a t i v e R e s p o n s e 1 0.8 0.6 0.4 0.2 0 400 550 600 650 700 Wavelength (nm) _____ - - - - - Light Meter Response CIE Response 450 500 6 LT300 V2.0 6/06