SC-100A help/advice

[Jim Welch]

I used my new Vinmetrica SC-100A yesterday to check SO2 levels. I followed Vinmetrica’s directions and used a stir plate. On my final sample something happened that I do not think is consequential but thought I’d see if anyone might know if this is so and maybe what happened
On my final sample as I added the Titrrant dropwise the tester finally went to a steady beeping state, after counting 15 beeps and seeing the stop light lit, I set down the syringe leaving the probe in the sample and started writing down the results.
Just then my three dogs started aggressively barking so I went outside to find out what they were barking at. When I returned probably two or three minutes later I found the tester no longer beeping and the green proceed light lit. My question then: is this test result valid? Is this to be expected under these circumstances, I.e. leaving the probe in the sample this long?

Thanks for reading.
Jim

 

[Jay A]

Jim, instructions for my 300 say test should be done under 3 mins. Not sure if a longer titration would cause your outcome. I yank the probe & power off the unit as soon as test is done, this eliminates any second guessing, which I always try to avoid in this hobby.

 

[mainshipfred]

While the magnetic stirrer moving the sample the free SO2 is being removed. I believe that is the reason for the recommended 3 minutes and why you had the results you had. Your initial reading should have been correct.

 

[Jim Welch]

Thank you gentlemen