HM Digital COM 100 - Question for B|Java

[crholliday]

I bought one of these to test out for everyone who has this on their Christmas list.

Anyone know how to use it?

Seriously, could you find out from your friend which setting he uses and what, if any, procedure he uses when measuring coffee? At first blush, my measurements are not what I would expect and I am simply following the instructions. I have been using PPM or PPT 442. My TDS results are coming in around 3000 ppm or .3% TDS. The variability is much less than I would expect as well. It could be that electricity may not be accurate enough for true coffee analysis - thus the refractometers used by the Mojo folks.

Any info you can get would be helpful!

[Ringo]

I use one at work to test boiler water but never put coffee in it.  3000 TDS for coffee sounds close to me.  In Ohio most well water is 300 to 1000 PPM.  These meters a very accurate.  High temp will make the readings off, so with boiler water you dump hot water in to preheat the probe then put another batch in and take your reading.  It will not read suspended solids.  If I was making drip coffee I would check my water before brewing then after brew, the difference between the two would be coffee.  When we check boiler water with a meter we have to add a rubbing alcohol to adjust PH to get a good reading.  Boiler PH is very high so I have no idea if that is needed before reading coffee but I do not think so. I have seen some talk at Sweet Marie on TDS meters.

[ecc]

I know this is not exactly what you are looking for, but hope it helps:
http://coffeegeek.com/forums/coffee/machines/372185?LastView=1227065615&Page=1

The short story, you likely need a calibration fluid.

[BoldJava]

I bought one of these to test out for everyone who has this on their Christmas list.

Anyone know how to use it?

Seriously, could you find out from your friend which setting he uses and what, if any, procedure he uses when measuring coffee? At first blush, my measurements are not what I would expect and I am simply following the instructions. I have been using PPM or PPT 442. My TDS results are coming in around 3000 ppm or .3% TDS...

Those numbers sound very high compared to those I have seen him log.  I will send you his email off line -- drop him a note.  I won't see him till Friday.