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Re: Aquatic Plants Digest V4 #286
In a message dated 5/16/2000 00:52:45 Pacific Daylight Time,
Aquatic-Plants-Owner at actwin_com writes:
> My pinpoint pH probe arrived today and there's no directions for
> it. There are directions on the calibration packets that read, "Immerese
> probe into solution." Ummm...ok....so do it before I connect the probe to
> the controller or after? How long is it supposed to say immersed? How
> often will I need to re-calibrate? I got packets of 4.000 and 7.000. I
> assumed this is what I needed after reading posts.
I use a Coralife pen probe, and it has calibration screws on top of the pen.
To calibrate, first rinse the pen well and gently shake. Then, immerse in
the 7.000 solution. There should be a 7.0 calibration screw on the
instrument somewhere. Let the probe settle into the solution for about 60
seconds, and then adjust the screw until the pen reads 7.00 (whatever the
resolution is). Rinse, gently shake dry, and immerse in the 4.000 solution,
and adjust that screw as well. You'll have to go back and forth a few times,
since adjusting one setting has a slight effect on the other setting. After
3 or 4 adjustments, the instrument SHOULD read 4.00 and 7.00 when in the
appropriate solutions. My pen doesn't hold its calibration precisely, and
tends to drift a slight bit over a period of months, so be sure to re-check
the calibration once every month or so until all components age and settle
into their long-term values. After that (about 6 months or so), the pen
should hold its calibration for extended periods of time.