1. Introduction
The REED Instruments R8140 LED Light Meter is designed for accurate measurement of ambient light levels. It is capable of measuring various light sources, including white, red, green, yellow, and blue LEDs, as well as standard incandescent light sources. This manual provides essential information for the proper setup, operation, maintenance, and troubleshooting of your R8140 light meter.
2. Safety Information
Please read all safety information before operating the device. Failure to follow these instructions may result in damage to the device or personal injury.
- Do not attempt to repair or modify the device. Refer all servicing to qualified personnel.
- Keep the device away from water and other liquids.
- Avoid exposing the device to extreme temperatures or direct sunlight for prolonged periods.
- Ensure correct battery polarity when installing batteries. Remove batteries if the device will not be used for an extended period.
- Dispose of batteries and the device according to local regulations.
3. Product Features
The REED R8140 LED Light Meter offers a range of features for precise light measurement:
- Measures ambient light levels of white, red, yellow, green, and blue LED light, as well as visible light in Foot-candles (Fc) or Lux (Lx).
- Large, backlit LCD display for clear readings in various lighting conditions.
- Detachable and rotatable light sensor for flexible positioning and one-handed operation.
- Auto-ranging feature to optimize measurement resolution.
- Min/Max function to record the lowest and highest readings.
- Data Hold function to freeze the current reading on the display.
- Cosine and color corrected measurements for enhanced accuracy.
- User-adjustable parameter for specialized light sources.
- Low battery indicator and auto shut-off function to conserve battery life.
4. Product Overview
Figure 1: Front view of the REED R8140 LED Light Meter. This image shows the main unit with its large LCD display, control buttons (Hold, Min/Max, Range, Set, fc/lx, Backlight), and the detachable light sensor connected via a coiled cable. The display currently shows a reading of 531 Lux.
4.1. Components
- Light Sensor: Detachable sensor with a protective cap, connected by a coiled cable.
- LCD Display: Large display showing measurement values, units (Lux/Fc), battery status, and function indicators (HOLD, MIN, MAX).
- Control Buttons:
- Backlight Button: Activates/deactivates the display backlight.
- HOLD Button: Freezes the current reading.
- MIN/MAX Button: Toggles between minimum, maximum, and current readings.
- RANGE Button: Manually selects measurement range (if not in auto-ranging).
- fc/lx Button: Switches between Foot-candles and Lux units.
- SET Button: Used for setting user-adjustable parameters.
- Battery Compartment: Located on the rear of the device.
5. Setup
5.1. Battery Installation
- Locate the battery compartment cover on the back of the meter.
- Slide the cover open or unscrew it, depending on the design.
- Insert two (2) AA batteries, ensuring correct polarity (+ and -) as indicated inside the compartment.
- Replace the battery compartment cover securely.
5.2. Sensor Connection
The R8140 features a detachable sensor. Ensure the coiled cable from the sensor is securely plugged into the corresponding port on the main meter unit. The sensor can be rotated for optimal positioning during measurements. Remove the protective cap from the sensor before use.
Figure 2: The REED R8140 LED Light Meter shown alongside its protective carrying case. The meter is ready for use, with its sensor connected and cap removed, indicating it's prepared for measurement or storage.
6. Operation
6.1. Power On/Off
Press the Backlight Button (red button with light bulb icon) briefly to turn the meter on. The meter will perform a self-test and display the current light reading. The meter features an auto shut-off function to conserve battery life after a period of inactivity. To manually turn off, press and hold the Backlight Button.
6.2. Selecting Measurement Units (Fc/Lx)
Press the fc/lx Button to toggle between Foot-candles (Fc) and Lux (Lx) measurement units. The selected unit will be displayed on the LCD.
6.3. Data Hold Function
Press the HOLD Button to freeze the current reading on the display. The "HOLD" indicator will appear. Press the HOLD Button again to release the reading and resume live measurement.
6.4. Minimum/Maximum (MIN/MAX) Function
Press the MIN/MAX Button to cycle through the minimum, maximum, and current readings recorded since the function was activated.
- First press: Displays the maximum reading ("MAX" indicator).
- Second press: Displays the minimum reading ("MIN" indicator).
- Third press: Returns to current reading (MIN/MAX indicators disappear).
To clear the MIN/MAX memory, press and hold the MIN/MAX Button until the indicators disappear.
6.5. Backlight Activation
Briefly press the Backlight Button (red button with light bulb icon) to turn the display backlight on or off.
6.6. User Adjustable Parameter
The R8140 allows for user-adjustable parameters to calibrate for specialized light sources. Refer to the detailed instructions in the full product manual (if available from the manufacturer's website) for advanced calibration procedures using the SET Button.
7. Maintenance
7.1. Cleaning
Wipe the meter body with a soft, dry cloth. Do not use abrasive cleaners or solvents. Keep the light sensor clean and free from dust or smudges, as this can affect measurement accuracy. Use a soft, lint-free cloth to gently clean the sensor dome.
7.2. Battery Replacement
When the low battery indicator appears on the display, replace the two (2) AA batteries as described in the "Battery Installation" section (5.1).
7.3. Storage
When not in use, store the R8140 in a cool, dry place, preferably in its protective carrying case. Remove batteries if storing for extended periods to prevent leakage. Ensure the protective cap is placed over the light sensor.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Meter does not power on. | Dead or incorrectly installed batteries. | Check battery polarity and replace batteries if necessary. |
| Inaccurate or fluctuating readings. | Dirty sensor; sensor cap still on; external light interference. | Clean the sensor. Remove the sensor cap. Ensure no direct light source is interfering with the sensor. |
| Display shows "OL" (Overload). | Light intensity exceeds the meter's maximum range. | Move the meter to an area with lower light intensity or ensure the correct range is selected (if not in auto-ranging). |
| Auto shut-off occurs too quickly. | Standard auto shut-off feature. | This is a power-saving feature. Refer to the full manual for information on disabling or adjusting auto shut-off if possible. |
9. Specifications
| Parameter | Value |
|---|---|
| Model Number | R8140 |
| Measurement Range | Up to 199,900 Lux (19,990 Fc) |
| Light Sources Measured | White, Red, Green, Yellow, Blue LEDs, Standard Incandescent |
| Display | Large, Backlit LCD |
| Sensor | Detachable and Rotatable |
| Functions | Auto-ranging, Min/Max, Data Hold, Backlight, User Adjustable Parameter |
| Power Supply | 2 x AA Batteries (included) |
| Dimensions | 6.7 x 2.5 x 1.5 inches (170 x 63.5 x 38 mm) |
| Weight | 7.41 ounces (210 g) |
10. Warranty and Support
10.1. Warranty Information
REED Instruments products are designed for reliability and performance. For specific warranty terms and conditions applicable to your R8140 LED Light Meter, please refer to the warranty card included with your product or visit the official REED Instruments website. Keep your proof of purchase for warranty claims.
10.2. Technical Support
Should you encounter any issues or require technical assistance with your REED R8140 LED Light Meter, please contact REED Instruments customer support. Contact details can typically be found on the manufacturer's website or in the product packaging.
