Today I received a Flinn digital thermometer for use in my AP tank that I will be using shortly. I tested the Flinn against two of my Legacy Pro glass thermometers and the Flinn is about 1F to 1.1F of a degree higher. The two glass thermometers register identically at 68F while the Flinn shows 69.1F Right now I am leaving a graduate with water sitting on the bathroom sink with the glass thermometers resting in it and then off-and-on checking with the Flinn.
When I did a few mock developing runs using plain water in the AP tank I noticed that the water jumps 0.6F higher after the water goes into the tank then there is a drift of 0.5F at almost the halfway point of a 12 minute process run. My original thought was that plastic tanks would hold temperatures more steadily over time than stainless tanks. The way I have been doing things, with stainless tanks, the developer comes back out from the tank as it went in, at 68F. Ambient temperatures of my room and bathroom are at 71F - 72F.
The Flinn doesn't have a calibration adjustment but it seems to stay at a consistent reading, relative to the other glass thermometers. With the Flinn you have to raise the thermometer up a little from the bottom of the graduate or the temperature reading will not be as accurate.
I was watching one of John Finch's videos where he used a digital thermometer halfway through the development cycle and gave an idea on compensation for developing times if temperatures should drift some. So thinking that I will be using the AP tank soon then I should try this technique.
So I guess my question now is: Which thermometer would be the accurate one? I have gotten great results with the glass ones that I have been using since 2019.
When I did a few mock developing runs using plain water in the AP tank I noticed that the water jumps 0.6F higher after the water goes into the tank then there is a drift of 0.5F at almost the halfway point of a 12 minute process run. My original thought was that plastic tanks would hold temperatures more steadily over time than stainless tanks. The way I have been doing things, with stainless tanks, the developer comes back out from the tank as it went in, at 68F. Ambient temperatures of my room and bathroom are at 71F - 72F.
The Flinn doesn't have a calibration adjustment but it seems to stay at a consistent reading, relative to the other glass thermometers. With the Flinn you have to raise the thermometer up a little from the bottom of the graduate or the temperature reading will not be as accurate.
I was watching one of John Finch's videos where he used a digital thermometer halfway through the development cycle and gave an idea on compensation for developing times if temperatures should drift some. So thinking that I will be using the AP tank soon then I should try this technique.
So I guess my question now is: Which thermometer would be the accurate one? I have gotten great results with the glass ones that I have been using since 2019.
