1. Fampidirana
The Extech LT40 is a compact and accurate LED Light Meter designed for measuring light levels from white LED light sources, as well as standard light sources. This device is essential for professionals needing to monitor and optimize environmental light levels in various settings such as offices, warehouses, public lots, hallways, and stairways. It provides measurements in both Lux and Foot-Candle (FC) units.

Figure 1: Extech LT40 LED Light Meter
2. Information momba ny fiarovana
Please read all safety information before operating the Extech LT40 LED Light Meter. Failure to follow these instructions may result in damage to the device or personal injury.
- Do not expose the meter to extreme temperatures or high humidity.
- Avoid dropping the meter or subjecting it to severe impact.
- Keep the sensor clean and free from obstructions to ensure accurate readings.
- Aza manandrana manokatra ny metatra casing; tsy misy kojakoja azo ampiasaina ao anatiny.
- Ario ny bateria araka ny fitsipika eo an-toerana.
3. Vokatra mihoatraview
3.1 Lafin-javatra fototra
- USB interface for easy setup and data download.
- Data azo safidiana sampling rates from 1 second to 24 hours.
- LCD displays current readings, min/max, and alarm status.
- Includes Windows 2000, XP, and Vista compatible analysis software.
- Measures white LED and standard lighting in Lux or Foot-Candle (FC) units.
- Features cosine and color corrected sensor for accurate measurements.
3.2 singa
The Extech LT40 LED Light Meter consists of the following main components:
- Fahazavana sensor: Located at the top of the meter, responsible for detecting light.
- LCD Display: Shows measurement readings, units, and status indicators.
- Bokotra fanaraha-maso:
- Bokotra hery: Turns the meter on/off.
- bokotra LUX/FC: Toggles between Lux and Foot-Candle units.
- CAL/ZERO Button: Used for calibration and zeroing the sensor.
- Bokotra MAX/MIN: Displays maximum and minimum recorded readings.
- Bokotra HOLD: Mampijanona ny famakiana ankehitriny eo amin'ny efijery.
- Efitra bateria: Ao ambadiky ny vondrona.
- Port USB: For connecting to a computer for data transfer.
4. Fametrahana
4.1 Fametrahana bateria
- Locate the battery compartment on the back of the LT40 meter.
- Sokafy ny fonon'ny bateria.
- Insert two (2) AAA batteries, ensuring correct polarity (+/-). The batteries are included with the meter.
- Akatona tsara ny fonon'ny batterie.
4.2 Fametrahana rindrambaiko
The LT40 includes analysis software compatible with Windows 2000, XP, and Vista. Refer to the software's installation guide for detailed instructions on installing and configuring the software for data download and analysis.
5. Torolàlana miasa
5.1 Mandray refy
- Tsindrio ny fahefana bokotra hampandeha ny metatra.
- Select the desired unit (Lux or FC) by pressing the LUX/FC bokotra.
- Place the light sensor in the area where you wish to measure the light level. Ensure the sensor is facing the light source directly for accurate readings.
- Read the light level displayed on the LCD.

Figure 2: Measuring light levels with the Extech LT40
5.2 Zeroing the Meter
To ensure accuracy, it is recommended to zero the meter before taking measurements, especially in low light conditions.
- Place the protective cap over the light sensor to block all light.
- Tsindrio ny CAL/ZERO button. The display should show '0' or a very low value.
- Remove the cap to begin measurements.
5.3 Using MAX/MIN and HOLD Functions
- MAX / MIN: Tsindrio ny MAX/MIN button to cycle through the maximum, minimum, and current readings. This is useful for monitoring light level fluctuations over time.
- HATAO: Tsindrio ny MANOHANA button to freeze the current reading on the display. Press it again to release the hold and resume live measurements.
5.4 Data Logging and Transfer
The LT40 supports data logging with selectable sampling rates. Connect the meter to a computer using the USB interface and utilize the included software to configure logging parameters, download recorded data, and perform analysis.
Vidéo: Vitaview of Extech LED Light Meters, including the LT40, demonstrating measurement capabilities and features like Lux/FC units and cosine/color corrected measurements.
6. Fikojakojana
Proper maintenance ensures the longevity and accuracy of your Extech LT40 LED Light Meter.
- Fanadiovana: Wipe the meter clean with a dry, soft cloth. Do not use abrasive cleaners or solvents. Ensure the light sensor is free of dust and debris.
- fitahirizana: When not in use for extended periods, remove the batteries to prevent leakage. Store the meter in a cool, dry place, away from direct sunlight and extreme temperatures.
- calibration: While the meter is designed for high accuracy, periodic professional calibration may be required depending on your application and industry standards. Refer to Extech's official support for calibration services.
7. Famahana olana
| OLANA | Antony mety hitranga | vahaolana |
|---|---|---|
| Tsy mandeha ny metatra. | Batterie maty na diso napetraka. | Check battery polarity. Replace batteries with new AAA batteries. |
| Vakiteny tsy marina. | Dirty sensor, incorrect zeroing, or sensor obstruction. | Clean the sensor. Perform a zero calibration. Ensure nothing is blocking the sensor. |
| Display shows "OL" (Overload). | Light intensity exceeds the meter's measurement range. | Move the meter to an area with lower light intensity or use a different meter if the light source is too strong. |
| Cannot connect to PC via USB. | Driver issues, incorrect cable, or software problem. | Ensure USB cable is properly connected. Reinstall the analysis software and drivers. Check PC's device manager. |
8. Famaritana
| famaritana | antsipirihany |
|---|---|
| Marika | Extech |
| Laharana modely | LT40 |
| Ny refin'ny vokatra | 5.3 x 1.9 x 0.2 santimetatra |
| Lanja entana | 4.94 oz |
| vatoaratra | Batterie AAA 2 (tafiditra) |
| Karazana fampisehoana | LCD nomerika |
| Teknolojia fifandraisana | USB |
| Endri-javatra manokana | High Accuracy |
| Anisan'ny singa | Extech LT40 LED Light Meter |
| Firenena nihaviana | TAÏWAN |
| KEVITRA | plastika |
| Met | CE |
9. Warranty sy fanohanana
Extech Instruments is a trusted brand by professionals, sold in over 100 countries for over 45 years.
- Mpanamboatra: Extech
- antoka: Refer to the manufacturer's official website or the documentation included with your product for specific warranty details and terms.
- User Manual (PDF): For a downloadable PDF version of the user manual, please visit the official Extech website or access it via this link: Extech LT40 User Manual PDF.
- Fanohanana an-tserasera: For additional support, FAQs, and product information, visit the official Extech store: Fivarotana Extech ao amin'ny Amazon.





