Not trying to be offensive? If you have to say that then you know you are. I read the instructions. Would you like me to print them for you? According to the instructions the 3 minute built-in timer is optional. You also get an instant reading AFTER it was already zeroed out and you can wait 3 mins on your own. I stated that in the first post.
I'm not contacting Hanna because, frankly, I'm not losing sleep over it. I was responding to the thread, not to you. The OP was asking about different readings. My post was another relevant method that's available for use on the unit that gives different readings.
After it's zeroed out, and wants C2, you can use the built-in timer or wait 3 mins and tap the button for the reading instead of holding it down, per the INSTRUCTIONS.
After holding it down and waiting, it gives a reading. If you then TAP the button after that reading, it gives it's instant reading as if you waited 3 mins and pressed the button yourself. That reading already accounts for it being zeroed out.
But thanks for the input Mr Hanna, but nowhere in your instructions does it say you cannot do that. It's simply using 1 option after another. We call it double checking. No offense.