Variations between meters

marzig

marzig

Member
I just got a complete and identical Apera pH/EC meter to have for a back up. I replaced the probe on my original as it was close to 2 years old 3 months ago. After cleaning and calibrating them both I decided to compare their readings. The temp, EC, and ppm are very close between them. But there is some difference in the pH readings and I'm wondering what's acceptable.

For instance 5.81 and 5.88. In my mind those are 5.8 and 5.9 rounded to the nearest 10th. In my work before retirement, I did a large amount of machining where tolerances of a 0.001" were critical so a 0.100 or 0.010 of an inch difference was huge.

Am I being to fussy or is the difference between 5.8 and 5.9 acceptable?
 
D

Delps8

Well-Known Member
You're not being fussy. The fact that you notice it and question it is it because that's who you've become.

"In my work before retirement, I did a large amount of machining where tolerances of a 0.001" were critical so a 0.100 or 0.010 of an inch difference was huge."
Understood (heh, we're the same age!). You made a living, for decades, by working to that standard. It's going to take time and effort to be able to compartmentalize that.

Repeat after me - "It's just a plant."

I'm a former artillery officer and have been a software engineer for 30+ years so, to me, it's either right or wrong. And it can't be "good enough, it has to be excellent. Oops, I mean "it's just a plant". ;-)

It took a while for me to accept that but, yeh, it's just a plant so 5.8'ish is good.

And I use a pH doser to keep it at 5.8 but that's because the doser makes it one less thing to deal with.
 
marzig

marzig

Member
Delps8 said:
You're not being fussy. The fact that you notice it and question it is it because that's who you've become.

"In my work before retirement, I did a large amount of machining where tolerances of a 0.001" were critical so a 0.100 or 0.010 of an inch difference was huge."
Understood (heh, we're the same age!). You made a living, for decades, by working to that standard. It's going to take time and effort to be able to compartmentalize that.

Repeat after me - "It's just a plant."

I'm a former artillery officer and have been a software engineer for 30+ years so, to me, it's either right or wrong. And it can't be "good enough, it has to be excellent. Oops, I mean "it's just a plant". ;-)

It took a while for me to accept that but, yeh, it's just a plant so 5.8'ish is good.

And I use a pH doser to keep it at 5.8 but that's because the doser makes it one less thing to deal with.
Click to expand...
It's just a plant, It's just a plant.

Thanks!
 
You must log in or register to reply here.
Top