COM-100 TDS Meter (2)

Response received from HM Digital.

The COM-100 does have automatic temperature compensation (ATC), but with very hot temperatures off the baseline of 25C, it will take some time for it to adjust.  You will either need to let the coffee cool, or allow the meter some time to stabilize.  There's no way around this.  The TDS level will be the same at any temperature - it's just a matter of giving the meter some time to adjust for temperature discrepancies...  It does not need to be 25 degrees, but the closer it is, the faster you can obtain the reading.

Good to get a response, but unfortunately it doesn't ease my mind about how useful the device is to me.  I've already unsuccessfully attempted leaving it for five minutes to reach a stable reading,  and if I need to let it cool to something like 50C (as a maximum) to get a credible reading then the coffee is no longer good for drinking.

The best I can envisage is that I adopt the following method:
1. Brew
2. Taste and assess
3. Leave to cool and take a reading at 25C
4. Discard the coffee
5. Try to replicate the parameters on future brews.

In theory that should be fine, since of course I don't want to measure every brew, but it also means that there's a slight disconnect between assessing the coffee's taste characteristics and obtaining a meter reading.  I wonder if this limitation is typical of all TDS meters, including refractometers.