DEF Refractometer Special Tool EN-50422
DEF Refractometer Special Tool EN-50422Description of the DEF Refractometer
The diesel exhaust fluid (DEF) refractometer (EN-50422) is used to determine the concentration of urea in diesel exhaust fluid in order to determine the quality of the fluid. Normally, the urea concentration should be 32.5% with no more than +/-3% variation. If water is added to the fluid, the concentration will become lower. As DEF ages, the concentration will become higher. If the DEF fluid falls outside of the 32% +/-4% range, the NOx sensors will determine an NOx reduction efficiency and a DTC will set.
DEF self life varies, but at room temperature it is estimated to be 1-2 years assuming the DEF fluid is tightly sealed at room temperature when stored.
Legend
(1) Eyeshade
(2) Calibration Adjustment Screwdriver
(3) DEF Refractometer
(4) Dropper
(5) DEF Stirring Rod
(6) Soft Cloth
Operating the DEF Refractometer
The DEF refractometer is simple to use and can be very effective in determining the quality of the DEF fluid. Follow the steps below to read the concentration of area using the DEF refractometer.
Legend
(1) Eyepiece
(2) Prism Surface
(3) Cover Plate
(4) Calibration Adjustment Screw
(5) Focus Adjustment knob
1. The DEF refractometer needs to be initially calibrated using ONLY pure distilled water at room temperature. A calibration was performed at time of manufacture, but should be performed when the tool is used for the very first time to ensure it was performed correctly. See Calibrating the DEF Refractometer below if this has not been done.
2. Using the soft cloth in the kit, wipe the prism surface and cover plate throughly, then open the cover plate so the prism surface is exposed.
3. Adjust the focus on the DEF refractometer by looking into the eye piece, holding the DEF refractometer body steady and turning the focus adjustment knob until the correct focus is achieved.
4. Stir the DEF fluid to be sampled using the DEF stirring rod.
5. Take a sample of the DEF using the dropper, then place a few drops of the sample over the prism surface and close the cover plate.
6. Look through the eye piece under good lighting to determine the concentration of urea in the DEF. You will see a light blue / white transition, which should occur at the 32.5% mark (within +/-3% is good).
7. Rinse and wipe down the prism surface at the end of the DEF refractometer use.
Calibrating the DEF Refractometer
1. Remove the calibration set screw cap to expose the calibration set screw.
2. Throughly rinse the cover plate and prism surface with room temperature pure distilled water. Use ONLY room temperature pure distilled water or the calibration will be incorrect.
3. Place a few drops of room temperature pure distilled water over the prism surface and then close the cover plate.
4. Look through the site glass and adjust the light blue / white transition line up or down by turning the calibration set screw until the transition occurs on the Waterline.
5. Reinstall the calibration set screw cap.