Elite NDT SA S291 Electronic Photofluorometer

Elite NDT SA S291 Electronic Photofluorometer

Faster, Easier & Accurate

The S291 Electronic Photofluorometer is specially designed to carry out fluorescence measurements faster, easier, and with higher accuracy. It has unique features like the zero and calibration adjustment with fine sensitivity potentiometer and digital display.

The S291 can also be used for ultraviolet and thermal stability tests on liquid penetrants. It can be used to measure the fluorescence of fluorescent and dual colored magnetic powders.

Measure of fluorescent brightness of penetrants as required by AMS 2644 (replacing MIL-I-25135), ASTM E-1417 (replacing MIL-STD-6866), EN ISO 3452-2. The NDT S291 is listed in ASTM E-1135 and completely meets the EN 571-2.


  1. Turn on the instrument and allow a 10 to 15 minute warm up
  2. Compare the prepared papers under the black light and choose one of the brightest papers to set the instrument.
  3. Place the chosen paper in the sample holder and insert the holder into the sample port of the photofluorometer.
  4. Adjust the meter response to 80 by turning the “CAL” adjustment knob.
  5. Remove the sample holder and replace the fluorescent paper with an untreated blank paper and re-insert into the instrument
  6. Adjust the meter response to 00 by turning the “Zero” adjustment knob.
  7. Remove the blank paper and insert the prepared sample for measurement. Alternate samples of test and standard material to minimize effect of any instrument drift that might occur.


Calculate the fluorescence of the test material as a percentage of that, of the standard material by the formula.

X/S × 100

X = the average of the test material reading
S = the average of the standard material reading


Technical Specifications

S291 Photofluorometer Specifications

Digital Display: LED 000 ÷ 999
Drift: Negligible
Lamp: UV Lamp 4 Watt 365 nanometers
Primary & Secondary Filters: In accordance with specifications
Zero Calibration: Fine potentiometers continuously adjustable (10 turns)
Power Supply: 100V - 230V, 50/60 Hz
Dimensions: 10.24" x 8.27" x 5.12" (260 x 210 x 130 mm)
Weight: 6.6 lbs. (3kg)
Reflectance Sample Holder: In accordance with specifications

S291 Photofluorometer Comes Complete With:

  • Sample Holder - Designed for insertion in the sample slot on the front of the photofluorometer.
  • Primary Light Filter - Integrally filtered long wave 4 watt lamp
  • Secondary Light Filters - Pre-installed OGR green and OB14 blue glass filters


Note: All units purchased for domestic use will be supplied with a U.S. Plug. All units purchased for use overseas will be supplied with open cable end (No plug included).
If plug is required, please specify when submitting request.

Product Literature

Description Part # Saved Price Select Option Add to
Elite NDT SA S291 Electronic Photofluorometer PT-ELNDT-S291 Request Pricing