I have used one (actually 2) of these machines. The upside is you can point to the print-out and tell your customers that you do test for cleanliness, and you pass. The reality of this test is that it tests for exactly 1 type of contamination.
The manufacturer sells a calibrated test solution that you can use to test your machine. Put the machine in test mode, put in the correct amount of fluid, add the contaminated drops, and watch your print-out to verify you are reading the "dirty" bath. If you see the graph register the contamination then everything is working as intended. If it still tests clean, you need a new sensor.
reply »