Refractometer

[McMullen]

This has probably been covered before, but a recent post made me think. How often are you checking or having to recalibrate your refractometer?

For at least the past three or four years I probably check only once or twice a year. Every time I check, my ATS is spot on, 35 or 0.026.

 

[Downbeach]

I used to check mine every WC, in my case every two weeks.

 

[Randy Holmes-Farley]

The need to recalibrate depends a lot on the individual refractometer.

If yours does not apparently drift, I wouldn't worry about it, BUT, I'd check it at least once a year (maybe more), and then also any time it gives a reading that suggests for you to take some sort of action, such as raising or lowering salinity.

 

[McMullen]

I keep it in the case under the tank, on top of the sump.

I'm curious if those who check calibration often are having to adjust?

 

[DeniseAndy]

Depends. Sometimes I check it monthly. Although, I rarely need an adjustment.

 

[jd371]

Mine drifts often, so I check it each time I use it.

 

[ed wicks]

I purchased one with temperature adjustment.purchased it through a chemical company,they recommend distlled water. I check it every 6 months

 

[McMullen]

What causes these things to drift? I would have thought keeping mine on top of my sump with high humidity would affect.