Author Topic: Extech pH100 - Time to settle?  (Read 243 times)

Offline Lloyd

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Extech pH100 - Time to settle?
« on: October 22, 2017, 06:28:26 AM »
Recently bought myself a second hand Extech ph100.  It seems to take a long time to take a reading when pressed against a cheese (Camembert style), slowly changing reading, even when it has stopped flashing. Is this normal behaviour?  (It is calibrated with both pH7 and pH4).

Thanks

Offline awakephd

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Re: Extech pH100 - Time to settle?
« Reply #1 on: October 22, 2017, 05:06:20 PM »
I find that it takes 15-30 seconds for the temperature to stabilize, especially if the probe is starting at a temperature far from the cheese.
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Offline Gregore

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Re: Extech pH100 - Time to settle?
« Reply #2 on: October 22, 2017, 09:49:29 PM »
Yes it will change readings until the fluid in the probe reaches close to the same temp and what you are trying to read.


Offline Lloyd

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Re: Extech pH100 - Time to settle?
« Reply #3 on: October 24, 2017, 12:05:53 PM »
Thanks.  So that implies that keeping the probe in the cave might be a good idea?

Offline awakephd

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Re: Extech pH100 - Time to settle?
« Reply #4 on: October 24, 2017, 01:57:29 PM »
Hmm - I typically am checking the pH at higher temperatures, where room temperature would be closer than cave temperature. I wash and dry the tip every time I use the meter, and washing in warm water tends to help shorten the settling time when checking warm curds.
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Offline Gregore

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Re: Extech pH100 - Time to settle?
« Reply #5 on: October 24, 2017, 11:22:23 PM »
There is not a whole lot of reasons to check the ph of a cheese after it is salted and in the cave .

If one is just curious as to ph change , then waiting a little for the temp to settle is okay.

If however you find it taking too long to settle when making cheese then put the cap on and hang it in the pot of warm curd  or a warm glass of water .

Offline Lloyd

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Re: Extech pH100 - Time to settle?
« Reply #6 on: October 25, 2017, 01:24:41 PM »
Hmm - I typically am checking the pH at higher temperatures, where room temperature would be closer than cave temperature. I wash and dry the tip every time I use the meter, and washing in warm water tends to help shorten the settling time when checking warm curds.

Actually that's a good point - its only the last time that I tried to measure that it had been in the cave, so ignore my last remark.  After sitting in the mould for a day the curd and the probe should be quite close in temperature, so it should not take too long to settle.  Will try a few more experiments on the next make with leaving the probe in buffer solution for a while before use (although I had expected the sponge in the cap to keep the probe from drying out)