hellbent77
Active Member
As an avid lurker, I've learned a lot from you all. I thought I'd post my stability test results to contribute a trifle at least. Maybe it'd help somebody decide what they want to buy or not buy.
I got the Hach Pro+ and used it for the first time yesterday. It came with only a few micro-specs of liquid in the sample cup. I missed the part of the instructions that said it should be "conditioned" in tap water for a couple of hours before use. Without doing this, I calibrated it twice and did a stability test yesterday. Stability test results were good for one hour (4.01 to 4.03) but got wobbly after that (rising to 4.11 after 3 hours).
Overnight I let it soak in Hach storage solution with the buffer containers nearby so they all came to the same temperature by morning.
This morning I calibrated again giving it 7 minutes to soak in 7.00 and 8 minutes to soak in 4.01 before saving the settings.
Then I did a stability test with the results below. The extra care taken helped a lot. It is so stable, I kept thinking the display lock was on. As I read in the lurked posts, it does take some practice to learn how to use it, to get confidence in your technique, and to get confidence in the meter.
Time is hr:min
Time pH Deg F
0:00 4.00 71.1
0:05 4.00 71.1
0:10 4.00 71.6
0:15 4.00 72.1
0:20 4.00 72.5
0:25 4.01 72.7
0:30 4.01 72.9
0:35 4.01 73.0
0:40 4.01 73.2
0:45 4.01 73.4
0:50 4.01 73.4
0:55 4.01 73.6
1:00 4.01 73.8
1:05 4.01 73.8
1:10 4.01 73.9
1:15 4.01 74.1
1:20 4.01 74.3
1:25 4.01 74.5
1:30 4.02 74.7
1:35 I tested some 7.63 pH pool water
1:40 4.05 75.4 <-- meter not stabilized after one minute soak in 4.01??
1:45 4.04 75.6
1:50 missed test time
1:55 4.02 75.7
2:00 4.02 75.7
2:15 4.02 75.9
2:30 4.02 75.9
2:45 4.02 75.9
3:00 4.02 75.9
3:30 4.02 75.7
4:00 4.02 75.6
5:00 4.01 74.7
5:40 4.01 74.5
I can't hover over it any more today. Maybe I'll let it sit all night and see what it looks like tomorrow morning.
Is there a way to read calibration info like slope % with autocalibration on the Pro+? I couldn't find a way on this unit.
Anyway hope the info helps or interests someone.
Cheers!
I got the Hach Pro+ and used it for the first time yesterday. It came with only a few micro-specs of liquid in the sample cup. I missed the part of the instructions that said it should be "conditioned" in tap water for a couple of hours before use. Without doing this, I calibrated it twice and did a stability test yesterday. Stability test results were good for one hour (4.01 to 4.03) but got wobbly after that (rising to 4.11 after 3 hours).
Overnight I let it soak in Hach storage solution with the buffer containers nearby so they all came to the same temperature by morning.
This morning I calibrated again giving it 7 minutes to soak in 7.00 and 8 minutes to soak in 4.01 before saving the settings.
Then I did a stability test with the results below. The extra care taken helped a lot. It is so stable, I kept thinking the display lock was on. As I read in the lurked posts, it does take some practice to learn how to use it, to get confidence in your technique, and to get confidence in the meter.
Time is hr:min
Time pH Deg F
0:00 4.00 71.1
0:05 4.00 71.1
0:10 4.00 71.6
0:15 4.00 72.1
0:20 4.00 72.5
0:25 4.01 72.7
0:30 4.01 72.9
0:35 4.01 73.0
0:40 4.01 73.2
0:45 4.01 73.4
0:50 4.01 73.4
0:55 4.01 73.6
1:00 4.01 73.8
1:05 4.01 73.8
1:10 4.01 73.9
1:15 4.01 74.1
1:20 4.01 74.3
1:25 4.01 74.5
1:30 4.02 74.7
1:35 I tested some 7.63 pH pool water
1:40 4.05 75.4 <-- meter not stabilized after one minute soak in 4.01??
1:45 4.04 75.6
1:50 missed test time
1:55 4.02 75.7
2:00 4.02 75.7
2:15 4.02 75.9
2:30 4.02 75.9
2:45 4.02 75.9
3:00 4.02 75.9
3:30 4.02 75.7
4:00 4.02 75.6
5:00 4.01 74.7
5:40 4.01 74.5
I can't hover over it any more today. Maybe I'll let it sit all night and see what it looks like tomorrow morning.
Is there a way to read calibration info like slope % with autocalibration on the Pro+? I couldn't find a way on this unit.
Anyway hope the info helps or interests someone.
Cheers!