1. Entwodiksyon
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. Enfòmasyon sou Sekirite
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.
- Do not attempt to open the meter casing; pa gen okenn pyès itilizatè a ka repare anndan an.
- Jete pil yo selon règleman lokal yo.
3. Pwodwi souview
3.1 Karakteristik kle
- USB interface for easy setup and data download.
- Done ki ka chwazi 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 Eleman
The Extech LT40 LED Light Meter consists of the following main components:
- Capteur limyè: Located at the top of the meter, responsible for detecting light.
- Ekspozisyon LCD: Shows measurement readings, units, and status indicators.
- Bouton kontwòl:
- Bouton pouvwa: Limen/etenn mèt la.
- LUX/FC bouton: Toggles between Lux and Foot-Candle units.
- CAL/ZERO Button: Used for calibration and zeroing the sensor.
- Bouton MAX/MIN: Displays maximum and minimum recorded readings.
- Bouton HOLD: Li bloke lekti aktyèl la sou ekran an.
- Lòj batri: Sitiye sou do inite a.
- Pò USB: Pou konekte ak yon òdinatè pou transfè done.
4. Enstalasyon
4.1 Enstalasyon batri
- Locate the battery compartment on the back of the LT40 meter.
- Glise kouvèti batri a louvri.
- Insert two (2) AAA batteries, ensuring correct polarity (+/-). The batteries are included with the meter.
- Fèmen kouvèti batri a byen.
4.2 Enstalasyon lojisyèl
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. Operasyon Enstriksyon
5.1 Pran yon mezi
- Peze a Pouvwa bouton pou limen mèt la.
- Select the desired unit (Lux or FC) by pressing the LUX/FC bouton.
- 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.
- Peze a 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: Peze a MAX/MIN button to cycle through the maximum, minimum, and current readings. This is useful for monitoring light level fluctuations over time.
- RETE: Peze a KENBE bouton an pou bloke lekti aktyèl la sou ekran an. Peze l ankò pou libere mezi yo epi rekòmanse mezi an dirèk yo.
5.4 Anrejistreman ak Transfè Done
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.
Videyo: Finiview of Extech LED Light Meters, including the LT40, demonstrating measurement capabilities and features like Lux/FC units and cosine/color corrected measurements.
6. Antretyen
Proper maintenance ensures the longevity and accuracy of your Extech LT40 LED Light Meter.
- Netwayaj: 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.
- Depo: 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.
- Kalibrasyon: 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.
NAN. Depanaj
| Pwoblèm | Kòz posib | Solisyon |
|---|---|---|
| Kontè a pa limen. | Pil ki mouri oswa ki mal enstale. | Check battery polarity. Replace batteries with new AAA batteries. |
| Lekti ki pa kòrèk. | Dirty sensor, incorrect zeroing, or sensor obstruction. | Clean the sensor. Perform a zero calibration. Ensure nothing is blocking the sensor. |
| Ekran an montre "OL" (Surchaj). | 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. Espesifikasyon
| Spesifikasyon | Detay |
|---|---|
| Mak | Extech |
| Nimewo Modèl | LT40 |
| Dimansyon pwodwi | 5.3 x 1.9 x 0.2 pous |
| Pwa atik | 4.94 ons |
| Batri | 2 pil AAA (enkli) |
| Kalite ekspozisyon | Digital LCD |
| Koneksyon Teknoloji | USB |
| Karakteristik espesyal | Segondè Presizyon |
| Konpozan ki enkli | Extech LT40 LED Light Meter |
| Peyi orijin | Taiwan |
| Materyèl | Plastik |
| Espesifikasyon Met | CE |
9. Garanti ak sipò
Extech Instruments is a trusted brand by professionals, sold in over 100 countries for over 45 years.
- Manifakti: Extech
- Garanti: Gade enfòmasyon ofisyèl manifakti a website or the documentation included with your product for specific warranty details and terms.
- Manyèl Itilizatè (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.
- Sipò sou entènèt: For additional support, FAQs, and product information, visit the official Extech store: Magazen Extech sou Amazon.





