American Marine Pinpoint pH probe

[SuperNerd]

If it is out of the water for some time does it become less accurate?

http://www.marinedepot.com/md_viewItem.asp?idproduct=AM1411

[bertoni]

Letting pH electrodes dry out has been known to cause problems, and I think that model has this limitation. You could ask American Marine about proper storage.

[SuperNerd]

Okay, so while the probe itself is damaged the monitor will still be just as accurate if the probe is replaced?

[bertoni]

Yes. Probes get replaced fairly regularly as they do wear out.

[SuperNerd]

How often do people replace them and does the same thing (out of water= bad thing) for a salinity monitor?

http://www.marinedepot.com/md_viewItem.asp?idproduct=AM1115

[SuperNerd]

Also, how long does the actual monitor last?

[bertoni]

Good question. I think it's much like any other electronic equipment. I would expect years.

[SuperNerd]

Okay.

How often do people replace the pH probes and does the same thing (out of water= bad thing) hold true for a salinity monitor?

http://www.marinedepot.com/md_viewItem.asp?idproduct=AM1115

[bertoni]

I use a general-purpose pH meter, and its probes last 6-12 months. The American Marine might last longer, since it's for saltwater only. I haven't had my salinity monitor long enough to wear out a probe. I think the American Marine probe can be stored dry, but I keep mine immersed anyway.

[jeffbrig]

I recently purchased a poinpoint monitor. The paperwork suggests to replace a probe when you can no longer calibrate it to read both a 4.0(or 10.0) and 7.0 test solution correctly. If I remember correctly, the useful life for a probe is estimated at about 18 months.

They also state that you should never let the tip dry out. Either keep it submerged in your tank, or fill the cap with storage solution (one of the calibration fluids is recommended for this).