calibrate PH probe 4.0, 5.0, 7.0, etc. ??

Met3112 · 07/23/2011, 09:55 AM

Hi everyone,
I have a milwaukee sms122 ph controller that needs to be calibrated.
It calls for calibration fluid at 4.0 and one at 7.0. I have the 7.0 but not the 4.0.
I have a few tunze calibration bottles that are brand new though. Can i use the 5.0 instead of the 4.0?

I dont understand why there are many different solutions. I am using the probe in a drip cup thats collecting effluent from my calcium reactor.

Thanks in advance for any help you can give.

disc1 · 07/23/2011, 10:49 AM

There are so many solutions because there are so many types of probes. Most probes can use 4.0, 7.0, and 10.0. Some probes are even able to tell by themselves which solution you have it in. With my ACIII, I can adjust the calibration buffer reading before I do the calibration.

With some instruments, the calibration points are set inside the program in the instrument. So they can only use buffers at certain values that they are expecting to see.

If you have the kind of instrument that will let you adjust it's calibration points (i don't think you do) then you could use 5 and 10. If not, then setting pH 4 equal to a real pH of 5 is going to cause all of your readings to be way way off.

Met3112 · 07/23/2011, 11:33 AM

Thanks for the reply. In the intructions it says to adjust the SLOPE calibration trimmer (on the rear) to display "4.0 ph" with 4.0 calibration fluid. What if i were to use the 5.0 and adjust it to 5.0. Whats the difference?
I know that you may not have experiance with this specific probe and controller. again thanks for the help.

07/23/2011, 09:55 AM	#1
Met3112 Registered Member Join Date: Mar 2009 Posts: 156	calibrate PH probe 4.0, 5.0, 7.0, etc. ?? Hi everyone, I have a milwaukee sms122 ph controller that needs to be calibrated. It calls for calibration fluid at 4.0 and one at 7.0. I have the 7.0 but not the 4.0. I have a few tunze calibration bottles that are brand new though. Can i use the 5.0 instead of the 4.0? I dont understand why there are many different solutions. I am using the probe in a drip cup thats collecting effluent from my calcium reactor. Thanks in advance for any help you can give.

07/23/2011, 10:49 AM	#2
disc1 -RT * ln(k) Join Date: Sep 2010 Location: Little Rock Posts: 9,705	There are so many solutions because there are so many types of probes. Most probes can use 4.0, 7.0, and 10.0. Some probes are even able to tell by themselves which solution you have it in. With my ACIII, I can adjust the calibration buffer reading before I do the calibration. With some instruments, the calibration points are set inside the program in the instrument. So they can only use buffers at certain values that they are expecting to see. If you have the kind of instrument that will let you adjust it's calibration points (i don't think you do) then you could use 5 and 10. If not, then setting pH 4 equal to a real pH of 5 is going to cause all of your readings to be way way off. __________________ David Current Tank: Undergoing reconstruction...

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07/23/2011, 11:33 AM	#3
Met3112 Registered Member Join Date: Mar 2009 Posts: 156	Thanks for the reply. In the intructions it says to adjust the SLOPE calibration trimmer (on the rear) to display "4.0 ph" with 4.0 calibration fluid. What if i were to use the 5.0 and adjust it to 5.0. Whats the difference? I know that you may not have experiance with this specific probe and controller. again thanks for the help.