Who is doing continuous mash pH monitoring?

[JKoravos]

I had written it off as a possibility long ago. It always seemed like it would be a PITA to do it simply, but now that I've gone down the microcontroller route a lot of things are opening up. Came across this the other day:

https://www.sparkfun.com/products/10972

$100 for continuous pH monitoring? uh, yes please. The freaking colorpHast strips are $30 a box. Not to mention a lot of the portable meter are well over $100. This kit is a steal. Anyone using it?

 

[motobrewer]

i bought a sensorex meter (plugs into my iPhone) but I was really eyeing up their process sensors.

http://www.sensorex.com/products/categories/category/process_ph_sensors

 

[vincentAlpha]

Damn I'd love to hook this up to a R-Pi with some temp sensors.

 

[orangehero]

I'd skip the kit. ±0.2 pH accuracy for the probe isn't exactly lab grade like they claim. Really that's the most important and expensive part. You can find cheap probes like that on ebay for less than $10. Nothing else there adds up to $95.

 

[JKoravos]

I'd skip the kit. ±0.2 pH accuracy for the probe isn't exactly lab grade like they claim. Really that's the most important and expensive part. You can find cheap probes like that on ebay for less than $10. Nothing else there adds up to $95.

Good point. I hadn't even got as far as looking at the specs. That being the case I'd probably go for a more accurate probe and buy the board separately. Only $30 or so.

 

[BlkWater_brewer]

The big problem you will find is that a pH probe is a rather expensive consumable. Continuous monitoring is really not a viable option unless you have a real need or extra cash. The action of taking a pH reading with a probe actually cases part of it to used up. It is not recommended to keep them in contact with the solution being monitored. This is especially true for the inexpensive probes, the expensive ones will last, but dam, they are expensive. Just my 2 cents.

 

[JKoravos]

The big problem you will find is that a pH probe is a rather expensive consumable. Continuous monitoring is really not a viable option unless you have a real need or extra cash. The action of taking a pH reading with a probe actually cases part of it to used up. It is not recommended to keep them in contact with the solution being monitored. This is especially true for the inexpensive probes, the expensive ones will last, but dam, they are expensive. Just my 2 cents.

Yes, that could be a problem. I'm aware of the fragile nature of the probes, but I don't have direct experience on longevity. I think it will come down to how long they last. I might just do spot checks if I'm eating them up too quickly. Obviously I don't really *need* continuous monitoring, but the system I'm putting together has datalogging capability so I'm interested in seeing what the pH profile looks like throughout the mash, but it may not be terribly interesting to record in the long term.

 

[trimixdiver1]

I have one in my HT and MLT loop. I also used the continually in my old reef tank with no issues. I clean out my lines then flush them with tap water for storage.

 

[JKoravos]

I have one in my HT and MLT loop. I also used the continually in my old reef tank with no issues. I clean out my lines then flush them with tap water for storage.

What type of probe are you using?

 

[trimixdiver1]

What type of probe are you using?

Wedgewood holder with broadly james probe

 

[RufusBrewer]

The big problem you will find is that a pH probe is a rather expensive consumable. Continuous monitoring is really not a viable option unless you have a real need or extra cash. The action of taking a pH reading with a probe actually cases part of it to used up. It is not recommended to keep them in contact with the solution being monitored. This is especially true for the inexpensive probes, the expensive ones will last, but dam, they are expensive. Just my 2 cents.

A probe gets used about 1 - 1.5 hours per mash, you brew a couple times a month. 36 hours a year. How long should somebody expect to a pH probe to last?

 

[ajdelange]

I'd skip the kit. ±0.2 pH accuracy for the probe isn't exactly lab grade like they claim. Really that's the most important and expensive part. You can find cheap probes like that on ebay for less than $10. Nothing else there adds up to $95.

It doesn't say the accuracy is ±0.2 pH. It says the offset is ±0.2 pH (about 11 mV). It is the function of calibration to measure that offset and provide it to the circuit which computes pH so that it can be accounted for. Accuracy ultimately depends on the quality of the A/D converter and temperature sensors used. I don't see a temperature sensor here so you will have to get temperature info elsewhere and feed that to what ever computation device calculates pH from temperature and probe voltage. Given decent rms voltage error (0.1 mV or so) and temperature error (0.5 °C is good enough) the concern then becomes probe stability IOW how long, given that the calibrated offset if 5.0 mV does it stay at 5.0 mV. In cheap meters the answer is often only a couple of minutes and that kills the accuracy unless you willing to calibrate every 5 minutes and that isn't practical in a continuous reading system.

Another problem here is that you will be exposing the electrode to continuous high temperature. This will shorten its life.