If you get the message VERIFICATION FAILED, see Figure 1, check that the prism and the sample holder are clean and the sample holder sits tightly on the sensor tip before a standard liquid is applied. Make sure the standard liquids are in good condition and not past their expiration date. Inspect the prism surface, make sure that it is smooth and glossy without any scratches. Go back to Verification step 2 by pressing REPEAT to the verification procedure.
The following are the most common reasons for verification failure:
- Insufficient cleaning of the prism.
- Too old calibration liquids
- Bad temperature control (changing temperature)
If verification fails even when repeating the verification procedure, fill in the sensor verification form (available in Appendix C) and send it to your nearest representative or email the collected information to helpdesk@vaisala.com and wait for further instructions.
For the sensor verification form collect data from the Verification step 2 display and the Verification results display. The sensor’s serial number is shown in the upper right corner of each display. The measured nD (RI) is given when VERIFY is pressed in Verification step 2. The list of CCD and TEMP values are on the verification results display, see the following figure.
