pH Meter: How long to get a reading?

[narcout]

A couple of months ago, I bought a Milwaukee MW101 pH meter.

One thing I wasn't expecting is that it takes about 2-3 minutes to get an accurate reading.  When I first insert the probe, the initial reading is usually around 7 or 8, and then it slowly starts going down until it eventually settles at the final reading.  I have found that gently stirring the probe in the sample speeds the process up a bit and actually seems necessary to get an accurate reading (as confirmed with testing solutions).

I've never heard anyone mention this before.  Is it normal or do I have a bad probe (it's only about 6 months old, and I store it in the recommended storage solution)?

[blatz]

not much to add - mine (same model) generally takes a few minutes to settle out as well - I await some of the pH meter experts to ring in.

[theDarkSide]

Not an expert but mine is usually at it's final reading in about 30-45 seconds, but then mine is el cheapo Milwaukee PH600 ( the yellow one ).

[blatz]

to be fair, it could be 45secs or 3 min - I usually am doing other stuff, keeping the corner of my eye on the readout until it looks like it has stopped before I pay attention.

I also found that swirling the probe in the wort solution helps speed things up.

[bluesman]

I have the same meter and I find that the reading settles out in about a minute or less. I am not concerned with a few tenths of additional settling as long as I can get a fairly stable reading (no more than a tenth or two drift over 20 seconds).

One thing that I want to point out is that I take all of my readings 10min into the mash, and I also chill my wort sample down to R.T. prior to taking a reading. I also calibrate my meter at 4.01 and 7.00 prior to taking a reading.

[euge]

I get a stable reading by swishing the probe around. Only takes a few seconds.