Precision Photometer

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Ideal for medical, laboratory, scientific and industrial precision light readings!

When used for mammography quality control of viewbox luminance and room illuminance, this device ensures that :

  • The luminance of viewboxes for interpretation or QC of mammography images meets or exceeds minimum levels.
  • Ambient illuminance levels are below prescribed levels.
  • Viewing conditions have been optimized


  • Checks x-ray viewbox and generator collimator light.
  • Check CT system light source
  • Measures light localizer illumination
  • Measures brightness and uniformity of a lightsource.


  • Easy to read digital display
  • Small, convenient to carry. Supplied with its own carrying case.
  • Rugged construction.

This Precision Photometer utilizes a filtered sensor with spectral response tightly calibrated to the CIE photopic response. The illuminance receptors closely follow the Cosine Law relative sensitivity versus angle of illuminance.

The Precision Photometer is a highly accurate instrument designed to measure both illuminance (the amount of light falling on a surface) in lux(lumens per m) and luminance (the amount of light emitted from a surface) in nit (candela per m).

The Precision Photometer easily and quickly verifies that an x-ray collimator light and/or CTsystem light source used for patient alignment and localization, is in accordance with regulations and guidelines. It also measures the brightness and uniformity of an x-ray viewbox, quickly detecting non-uniformity (which may appear as artifacts, causing misdiagnosis). This battery-operated photometer has a bright LED display and only two operating controls: "Measure" for taking a reading, and "Range" to adjust the meter display to the light level being measured.

Principal Features

Measure Button: Press it to get continuously updated readings. Releasing the measure button freezes the last reading for convenient reference.

Range Button: Adjusts the measurement display for the resolution desired.

LED Display: Visible in very dim light, as well as direct sunlight. LEDdisplays are inherently robust in comparison to LCD (liquid crystal) displays.

The battery-powered photometer provides tens of thousands of readings.


  • Capabilities - Iluminance measured in lux (foot-candles); or luminance measured in candela/m (nit).
  • Readout display - Three-digit LED, " high
  • Range - 0.1 to 999.000 lux or nits (candela/m), equivalent to 0.01 to 99,000 foot candles.
  • Accuracy - Within 7% of full scale range, for light sources between 2500 degrees and 5400 degrees Kelvin
  • Electrical Accuracy - 1% plus 2 digits
  • Sensor - Silicon photodiode with photometric filter
  • Response Curve Shape - Close match to CIE photopic response curve
  • Batteries - Type A-76 alkaline button cells or silver oxide equivalents
  • Dimensions - 4" H x 2/8" W x 1.2" thick (10 x 7 x 3 cm)
  • Weight:4 oz (120 g)

0695-0087 Precision Photometer with carrying case
0695-0088 Flexible 12-inch Fiberoptic Probe (must be calibrated meter)
0695-0089 1 Rigid Fiberoptic Probe(must be calibrated with meter)
0695-0090 Rotating Illuminance Receptor (must be calibrated with meter)
0695-0091 Storage/Carrying Case

Factory recalibration available. Price on request.