Radiometry is the measurement of radiation in the electromagnetic spectrum. This includes ultraviolet (UV), visible and infrared (IR) light.
Radiometric measurements quantities include: Radiant Flux (Watt); Radiant Intensity (W/sr); Irradiance (W/m2); Radiance (W/m2sr)
- Radiant Flux Measurements (in units of watts) are performed with an instrument known as a flux meter or optical power meter. This type of testing is typically used for characterizing the total output of sources such as:Lasers, LEDs, Lamps and Fiber-Optic Systems
- Irradiance Measurements (in units of W/m2) are performed with an irradiance meter. This involves the measurement of the radiant flux incident upon a surface, per unit area. Such measurements are important in the following fields: Medical, Biological and Remote Sensing
- Radiant Intensity Measurements (in units of W/sr) are performed with an instrument that may be described as an optical intensity meter. This type of testing is typically used for characterizing the output of a relatively small source in a particular direction. Typical devices under test include: LEDs, UV Lamps and IR Lamps
- Radiance Measurements (in units of W/m2sr) are performed with a radiance meter. This involves measuring the light emitted in a particular direction by a given spot on the surface of an extended source. Such measurements are important in fields such as: Remote Sensing, Avionics and Night Vision
UDT Instruments, a division of Gamma Scientific, offers an extensive selection of radiometers, radiance meters, irradiance meters and optical sensors to meet your radiometric test and measurement needs.
Combining our wide range of optometers, radiometric sensors and accessories, with our state-of-the-art calibration facilities, allows our applications engineers to assemble and configure custom radiometer systems for nearly any project.
Specifying a Radiometer System
Selecting a properly calibrated radiometric head and the right readout device are important in obtaining accurate results.
The sensor head converts electromagnetic radiation into an electrical signal. The readout device then receives this signal and interprets it. A properly calibrated measurement system will measure the light source and display the measurement in the appropriate optical units.
The readout unit should be selected according to its features, and the detector head should be selected according to its power measurement range, wavelength calibration and size. The two matched together will accurately measure the source in the correct optical units.
Radiometer and Radiometry Resources from Gamma Scientific
- UDT Instruments Guide to Radiometry (Free PDF Download)
- Radiometer System Configurations(PDF)
- How to Characterize a Spectral Radiometer
Gamma Scientific Radiometers and Radiometric Sensors
flexOptometer Benchtop Radiometer
High-performance radiometer designed to operate as a stand-alone instrument or computer-controlled radiometric measurement system. Available with a single head, or up to four interchangeable detector heads. Electronic design is based on Gamma Scientific’s TIA-3000 measurement system, which serves as the primary working standards of several National Standards Labs. Laboratory grade accuracy and durability ensures that the flexOptometer will operate in the most rigorous production line environments.
The NVG-4040 has a unique ability to perform NVIS-A, NVIS-B and NVIS-C radiance measurements. Lightweight, portable and cost-effective, it conforms to MIL-L-85762A and MIL-STD-3009. The NVG-4040 is optimized for a full range of photopic applications, and is ideally suited for measuring displays and instrument panels used with night-vision goggles.
The model 471 handheld radiometer is designed to be used for radiometric measurement in the laboratory or field testing environment. It features high-accuracy measurements, wide dynamic range, high-speed update rate and a large calibration capacity. All calibrations are traceable to the National Institute of Standards Technology (NIST).
Detector-based absolute standards for capturing a wide range of measurements. Configurations include thermo-electrically cooled silicon and indium gallium arsenide (InGaAs) detectors with options for radiometric correction filters, flat-response filters, trap detectors and ANVIS-compatibility filters. Standard calibrations, directly traceable to NIST, are available for any configuration of the TIA-3000 from Gamma Scientific’s world-renowned standards lab.
Radiometric Sensors from UDT Instruments
UDT Instruments produces precision radiometric sensors for diverse applications and are ideally suited for OEMs and value-added resellers. UDTi radiometric sensors provide industry leading accuracy, and each sensor from UDT Instruments includes a NIST-traceable calibration from our NVLAP accredited laboratory.
uRAD-LL Handheld Radiance Meter
This radiance meter bundle combines a filtered silicon sensor with a fixed-focus lens to provide non-contact radiance measurement of an area on the surface of an extended source. Spot size is dependent working distance, which ranges from 17 mm to infinity.
This irradiance meter bundle combines a broadband silicon sensor with a benchtop optometer to provide simple and accurate measurement of irradiance. The system’s calibration is programmed into the benchtop optometer. Measurement results are displayed by the optometer in units of Watts per square meter (W/m2), and digital data can be acquired directly via PC.
Photosensors can be equipped with various types of optical accessories to form sensor head assemblies suitable for diverse types of measurements. UDT Instruments offers a range of preconfigured sensor heads, as well as the following optical components to enable configuration of custom sensor heads for the measurement of flux, illuminance, irradiance, intensity, luminance, or radiance.
