What is the best way to calibrate dual pH probes?

lvreefer · 05/01/2007, 11:33 AM

Help me calibrate pleaseâ€¦

I am using two pH probes with an ACIII. Both are connected directly to the controller (pH BNC & ORP BNC) and not through a PX 1000 port expansion. For the longest time it was working and since the last firmware upgrade (3.10S - 7A06 to 3.20S - 1A07) it has been slowly going lower and lower (I have a ground probe in sump). In the past I have calibrated both probes at the same time in; Both in the 7, step through probe one setting, then both in 10, step through probe one setting till set. Then do the same for probe 2, using both probes.
Do I need to recalibrate a different way or has one of my probes gone bad, causing the other one to act sporadically? Is there a better method? Will I get more consistent results using the port expansion PX 1000 with one pH probe connected to the ACIII and the other into the pH port on the PX 1000?

Thanks!!

clp · 05/02/2007, 10:11 AM

The calibration procedure sounds fine. Double check that they are calibrated properly. After calibration go to the run display and make sure that they read the 7.0 and 10.0 calibration solutions correctly.

Curt

lvreefer · 05/02/2007, 10:17 AM

Thank you.

05/01/2007, 11:33 AM	#1
lvreefer Registered Member Join Date: May 2003 Location: Sin City Posts: 1,163	What is the best way to calibrate dual pH probes? Help me calibrate pleaseâ€¦ I am using two pH probes with an ACIII. Both are connected directly to the controller (pH BNC & ORP BNC) and not through a PX 1000 port expansion. For the longest time it was working and since the last firmware upgrade (3.10S - 7A06 to 3.20S - 1A07) it has been slowly going lower and lower (I have a ground probe in sump). In the past I have calibrated both probes at the same time in; Both in the 7, step through probe one setting, then both in 10, step through probe one setting till set. Then do the same for probe 2, using both probes. Do I need to recalibrate a different way or has one of my probes gone bad, causing the other one to act sporadically? Is there a better method? Will I get more consistent results using the port expansion PX 1000 with one pH probe connected to the ACIII and the other into the pH port on the PX 1000? Thanks!!

05/02/2007, 10:11 AM	#2
clp RC Sponsor Join Date: Aug 2001 Location: San Jose, CA Posts: 4,311	The calibration procedure sounds fine. Double check that they are calibrated properly. After calibration go to the run display and make sure that they read the 7.0 and 10.0 calibration solutions correctly. Curt

05/02/2007, 10:17 AM	#3
lvreefer Registered Member Join Date: May 2003 Location: Sin City Posts: 1,163	Thank you.