FEL Irradiance Standards

Optronic Laboratories FEL Spectral Irradiance Standard Lamps Overview

Pro-Lite supplies 1000 Watt FEL irradiance standard lamps from Optronic Laboratories (OL). Screened, seasoned and calibrated FEL standards are quartz tungsten halogen lamps that are used as reference sources of spectral irradiance and illuminance that are used to calibrate photometers, colorimeters and spectroradiometers. The name “FEL” is not an acronym but a designation from the American standards organisation, ANSI.

Each of the OL 1000-W FEL lamps have a tungsten coiled-coil filament enclosed in a small quartz envelope. The lamp bases have been converted to a medium bi-post base as recommended by the National Institute of Standards and Technology (NIST). This special lamp base improves alignment accuracy, which minimises uncertainties due to positioning and orientation of the lamp. The OL FEL series use the OL 410-1000 Precision Lamp Source and OL 61 Lamp Holder. We also recommend the OL 62 FEL Alignment Jig and OL 63 Adjustable Lamp Holder Mount

To ensure that a calibration lamp is not operated beyond its rated life, the operator is strongly recommended to maintain a logbook of when each lamp is used and for how long. Operating a standard lamp beyond its rated life risks increasing the rate of lamp depreciation, and hence invalidating its calibration. The use of a “soft ramp”, current regulated, DC power supply is highly recommended. By gradually increasing the current that you apply to the calibration lamp, you minimise the thermal shock to the filament and help maintain the lamp’s calibration over a longer period. A current regulated power supply maintains a stable lamp output – the flux emitted from an incandescent lamp varies non-linearly with the current applied.

Ordering Information

The OL range of FEL lamps can be ordered as a screened but uncalibrated lamp, or calibrated spectroradiometrically over a variety of wavelength ranges. Choose from calibrations of spectral irradiance between 250-750nm, 250-1100nm, 250-2500nm, 250-3000nm, 250-4500nm and 750-2500nm. In addition, you may choose a lamp with just a total irradiance calibration, or a lamp calibrated for both illuminance and spectral irradiance from 250-2500nm.

• OL FEL-A Irradiance Standard (250-750nm)
  The Optronic Laboratories FEL-A is a 1000-W irradiance standard with a spectral irradiance calibration from 250 to 750nm.
• OL FEL-B Irradiance Standard (750-2500nm)
  The Optronic Laboratories FEL-B is a 1000-W irradiance standard with a spectral irradiance calibration from 750 to 2500nm.
• OL FEL-C Irradiance Standard (250-2500nm)
  The Optronic Laboratories FEL-C is a 1000-W irradiance standard with a spectral irradiance calibration from 250 to 2500nm.
• OL FEL-D Irradiance Standard (Total Irradiance)
  The Optronic Laboratories FEL-D is a 1000-W irradiance standard with a total irradiance calibration.
• OL FEL-H Irradiance Standard (Total & Spectral Irradiance, 250-2500nm)
  The Optronic Laboratories FEL-H is a 1000-W irradiance standard with a total irradiance calibration and a spectral irradiance calibration from 250 to 2500nm.
• OL FEL-IR Irradiance Standard (250-4500nm)
  The Optronic Laboratories FEL-IR is a 1000-W irradiance standard with a spectral irradiance calibration from 250 to 4500nm.
• OL FEL-M Irradiance Standard (250-1100nm)
  The Optronic Laboratories FEL-M is a 1000-W irradiance standard with a spectral irradiance calibration from 250 to 1100nm.
• OL FEL-N Irradiance Standard (250-3000nm)
  The Optronic Laboratories FEL-N is a 1000-W irradiance standard with a spectral irradiance calibration from 250 to 3000nm.
• OL FEL-P Illuminance Standard (Illuminance & Spectral Irradiance, 250-2500nm)
  The Optronic Laboratories FEL-P is a 1000-W irradiance standard with a total illuminance and a spectral irradiance calibration from 250 to 3000nm.
• OL FEL-U Screened Standard (Uncalibrated)
  The Optronic Laboratories FEL-U is a 1000-W uncalibrated standard lamp.