Light Meter with Thermal Radiation Sensor Lux/UV/Temp/Infrared

UV light and fluctuations in temperature and humidity can be particularly damaging for works of art, textiles, indeed most historic objects. Monitoring and metering of environmental conditions ensures curators and conservators can make the correct adjustments necessary to reduce exposure and regulate fluctuations.

This single meter (684-775C & 684-775) measures:

Thermal Radiation (IR)

The measurement of thermal radiation (shown as W/M2) allows the user to estimate how much solar heat is coming through windows, check the performance of heat reflecting films, measure the heating effect of lamps on objects etc.

Ultraviolet (UV)

For many years it has been recognised that one of the major causes of damage to museum objects and other sensitive objects, soft furnishings etc is the fading and rotting effect of light on the object. The most damaging part of the illumination is its ultraviolet content. Using the 775, measurements can be taken of the proportion of UV present (µW/lumen), the total amount of UV (mW/M²)

Visible Light

The amount of visible light is important, not only to check illumination in work areas, galleries etc but also to control damage to light sensitive objects that is also caused by normal light. Measurements can be displayed as Lux or Foot-candles.


The meter is also available with a data logging function (684-775C only). Enabling over 73,000 readings of all four parameters to be automatically taken at selectable intervals (every 10 seconds to 1 hour). The saved data can then be transferred to a computer by a standard USB interface. When logging data the 775 can be turned off to save power and the built in clock will turn the unit on whenever a reading needs to be taken, this enables a 775 to be left taking readings for months at a time. Software is provided to display the measurements as graphs or text. Data is saved in CSV format that can be accessed and displayed by many programs (e.g. Microsoft Excel).

Code Description Pack Size Price Stock QTY
P684-775C 684-775C Universal Light Meter/Logger Each £705.00 (ex VAT) In Stock
P684-775 684-775 Universal Light Meter Each £585.00 (ex VAT) Low Stock
Specification Recommended Alternatives

  • Visible wavelength range | 400-700nM (CIE response). No correction required for different light sources.
  • Visible power range | 0.1 - 200,000 Lux (0.1 – 20,000 Foot-candles)
  • UV wavelength range | 300 - 400 nM
  • UV power range | 2 - 10,000 mW/M2
  • UV proportion range | 0 - 10,000 mW/Lumen
  • Thermal radiation sensor | Bismuth/Antimony thermopile with KBr window
  • IR/Thermal wavelength range | 350nM - ~40μM
  • Display resolution:
    Lux: 0.1 up to 100 then 1
    Foot-candles: 0.1 up to 100 then 1
    UV: 0.1 up to 100 then 1
    Proportion of UV: 1 mW/Lumen
    Temperature: 0.1°C or °F
    IR: 0.1 up to 100 then 1
  • Accuracy Visible: 5% ±1 displayed digit
    UV: 15% ±1 displayed digit
    Temperature: ±0.5°C (±0.9°F)
    IR: 5% ±10W/M2
  • Angular response (Light & UV) | Cosine
  • Readout | 128x64 OLED Display with automatic brightness control
  • Computer Interface | USB “flash disk”
  • Date functions | Display as day-month-year or month-day-year.
  • Batteries | 4 no. NiMH AAA type.
  • Battery Life | Approx 25 Hours continuous use (3,000 readings taking 30 seconds each) or over 100,000 log readings.
  • Charger Input | 100-240V 50-60Hz Output: 5V (USB connector)
  • Operating Temperature | 0-50°C 0-99%RH, non condensing
  • Dimensions | 170 x 60 x 15mm 6.7 x 2.4 x 0.6 inches Including RH/Temperature probe
  • Weight | 240g (8.5 oz) with batteries.

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