Roseman
Elite Rolling Society
One of the most aggrevating things I've ever attempted was calibrating a pH meter.
Makes me want to just pee straight up!
And what makes it worst, is having two pH meters to compare results.
Let me give you a heads up about calibrating a pH meter and using it. You have to just use it as a "rule of thumb" so to speak, and use it to try to stay within range.
For those that already know and those that do not, you can put an expensive $54 super-duper pH meter in water, test it, read it, get 6.8 and take it out, stick it back in, and it will be a little different, like 6.6. Shake it around in the water, stir it in the water and you'll get a different results, like 6.4, in the exact same water. Then take it out of the water, turn it off, and put it back in the same water, turn it back on in the water, and read 6.5, blow on it and get 6.9.
Temperature of water makes a big difference in the pH of water.
Shaking and stirring the meter in the water, makes a slight difference.
Turning it on IN the water and turning it on OUT of the water, makes a slight difference.
Turning it OFF and ON in the same water, makes a difference.
Waiting three minutes yields a different reading too.
I had year old calibration solution, but it was still clear looking and smelled OK. I used it and adjusted my meter, and then I used it and adjusted my meter, and then I used it and adjusted my meter, and then I used it and adjusted my meter, and then .......well,,,that took an hour.
I would put it in the 4.0 solution, get it to read 4.0 by adjusting it, (there is a SET SCREW you turn to make it go up or down) then put it in the 6.8 solution, it would read 7.1, I 'd turn it down to make it say 6.8, then try it again in the 4.0 and it would read 3.7!
After I spent an hour, spliting the difference, going back adn forth, it was very close to accurate to the calibration solution. In 6.8, it read 6.7, and in the 4.0, it read 4.1. Sounds good enough, huh?
Then, I checked it with my old meter, and good grief! The old meter said the 4.0 was 3.5 and the 6.8 was read as 6.2.
Took another hour to get the two meters to agree within .5 difference, which is really a broad difference, but one I will accept.
AND I am not even going to compate them to the tEST STRIPs tonight, although I will later.
If you ever want to really drive someone crazy, or start them drinking early, buy them TWO pH meters, and ask them to adjust and calibrate them to perform the same.
Anyway, I got two pH meters, fairly close to reading the smae, but not really. What's a pot head to do?
The pics show my efforts.
Attached Thumbnails
Makes me want to just pee straight up!
And what makes it worst, is having two pH meters to compare results.
Let me give you a heads up about calibrating a pH meter and using it. You have to just use it as a "rule of thumb" so to speak, and use it to try to stay within range.
For those that already know and those that do not, you can put an expensive $54 super-duper pH meter in water, test it, read it, get 6.8 and take it out, stick it back in, and it will be a little different, like 6.6. Shake it around in the water, stir it in the water and you'll get a different results, like 6.4, in the exact same water. Then take it out of the water, turn it off, and put it back in the same water, turn it back on in the water, and read 6.5, blow on it and get 6.9.
Temperature of water makes a big difference in the pH of water.
Shaking and stirring the meter in the water, makes a slight difference.
Turning it on IN the water and turning it on OUT of the water, makes a slight difference.
Turning it OFF and ON in the same water, makes a difference.
Waiting three minutes yields a different reading too.
I had year old calibration solution, but it was still clear looking and smelled OK. I used it and adjusted my meter, and then I used it and adjusted my meter, and then I used it and adjusted my meter, and then I used it and adjusted my meter, and then .......well,,,that took an hour.
I would put it in the 4.0 solution, get it to read 4.0 by adjusting it, (there is a SET SCREW you turn to make it go up or down) then put it in the 6.8 solution, it would read 7.1, I 'd turn it down to make it say 6.8, then try it again in the 4.0 and it would read 3.7!
After I spent an hour, spliting the difference, going back adn forth, it was very close to accurate to the calibration solution. In 6.8, it read 6.7, and in the 4.0, it read 4.1. Sounds good enough, huh?
Then, I checked it with my old meter, and good grief! The old meter said the 4.0 was 3.5 and the 6.8 was read as 6.2.
Took another hour to get the two meters to agree within .5 difference, which is really a broad difference, but one I will accept.
AND I am not even going to compate them to the tEST STRIPs tonight, although I will later.
If you ever want to really drive someone crazy, or start them drinking early, buy them TWO pH meters, and ask them to adjust and calibrate them to perform the same.
Anyway, I got two pH meters, fairly close to reading the smae, but not really. What's a pot head to do?
The pics show my efforts.
Attached Thumbnails
