Hi,
I have just gotten a PH meter that comes with 2 calibration solutions. One for PH 4 and the other for PH 6.86. As per the instructions, i was supposed to calibrate the meter first with the PH 6.86 solution and then calibrate it with the PH 4 solution. However, wont calibrating based on two different points affect the overall accuracy of the PH meter?
After i calibrated based on 6.86, when i tried the PH 4 solution it was off also. So i calibrated based on the PH 4 solution, but then the reading on the 6.86 becomes off now. Any advise? Also the results on the PH meter are very different from the PH gotten from API test kit.
Make sure you rinse the PH meter probe unit in distilled water to wash away the residual calibration solution, before testing with the other calibration solution, it should eliminate cross contamination and odd measurements.
Otherwise, if the calibrations keep encountering problems, maybe the calibration solutions that came packaged with the meter were somehow expired or something. You may consider getting another new set of calibration solutions to do the tests and adjustments.
Thank you for the advise! I did wash the tester in RODI water as per the instructions, but that didnt seem to help. Also the main thing is why do they provide two separate PH testing solutions? No matter how you do it, one PH result will always be off. I don't understand the logic, can anyone explain the purpose of 2 PH test solutions?
Baton courtesy.....service with a smile!
Actually, a ph meter has 3 calibration solution, ph 4, ph 7 and ph10 ( I think ). If you are using for lower ph, you need to calibrate with the ph4 and ph7 calibration solution. For testing a higher ph water, you need to calibrate with the ph7 and ph10 calibration solution. As far as I know, there are no single calibration solution to cover the whole ph reading.
If you've learnt, teach, if you have, give.
Don't walk behind me as I might not lead, don't walk in front of me as I might not follow. Walk beside me, as my friend.
Mohamad Rohaizal is my name. If it's too hard, use BFG. I don't mind.
Most PH meters are recommend to go though 2 point testing and calibration regularly, that is to ensure that the meter is working properly. The 2 different pH solutions are meant to confirm the calibration. If the meter can't be calibrated correctly with 2 different pH solutions, then it indicates that something wrong with the meter (or maybe the calibration solutions).Originally Posted by junwei38
Many calibration test kits come with 3 pH solutions... 4.0, 7.0 and 10.0 (there might be some slight variations in exact pH test values depending on kit). Usually if you are measuring more of lower pH conditions, then test with 4.0 and 7.0 solutions. If measuring more of higher pH conditions, then calibrate with 7.0 and 10.0 solutions.
Anyways, there is always a possibility the meter itself is faulty, thats what the calibration tests are meant to check. If its faulty, then just have to exchange it at the LFS for a new working unit.
Your Ph calibration media come in solution or powder base? What kind of Ph meter is that?
Some Ph meter will not read accurately when there is some sort of electronic interference such as light ballast.
try to change the battery of your PH meter...
my brand new PH meter cannot get the reading I want, after many tries, I changed to brand new sets of batteries, it works fine after that.
Yes, especially those PH meter with 2 in 1 feature, it will get some interference. I noticed this when i repositioned my probe at different locations in the tank.
Also check if the probe is inserted properly and if it is clean.
Posting Permissions
Reply With Quote
Bookmarks