Refractometer vs Salinity Monitor

[cali_reef]

You cannot use a salinity standards intended for conductivity meters to calibrate refractometers.

I don't see what you quoted says that?

 

[pecan2phat]

I have used the 53 ms solution on a 0 calibrated (distilled water) refractometer and it reads 1.026 like a gem so I don't see why you cannot use it?

 

[herman]

I have used the 53 ms solution on a 0 calibrated (distilled water) refractometer and it reads 1.026 like a gem so I don't see why you cannot use it?

Same here!

 

[alrha]

I don't see what you quoted says that?

You cannot use a salinity standards intended for conductivity meters to calibrate refractometers.

second to last post by Randy Holmes-Farley (02/17/2005 03:42 PM):

I've not seen Pinpoint sell refractive index standards, but perhaps they do and do not list them on their web site.
You cannot use a salinity standards intended for conductivity meters to calibrate refractometers.

from this thread:

ok, found another thread and found that Randy was not using the [relatively] cheap pinpoint monitor but rather the [more] expensive orion monitor. http://reefcentral.com/forums/showthread.php?s=&threadid=530030&highlight=Captive+Purity+Refractometer

 

[alrha]

well, i got my refractometer today!

using it, i discovered that my SG was at 1.030! My pinpoint monitor was reading at 1.025 - and i was actually trying to raise it a bit to 1.026!

Needless to say i recalibrated the monitor and it is reading properly now, but i will know not to rely on it.

I am now in the process of slowly loweing my SG.

Cali, i would like to thank you for pointing out to me that my SG was high when i brought you that fish. i thought it was just due to evaporation (& no top-off) on my QT tank.

I didnt need to calibrate it as it seemed to be spot on, but the instructions said that it must be calibrated at 68F - too bad i dont keep my A/C that low, is it really that important to calibrate at that temp? how different would that be from say 72-76? significantly off?

lastly, i am aware that the drops of water must cover the entire glass before reading it, how anal must one be about it? as it is not always so easy to cover it entirely, there is always a tiny corner here or there that remains uncovered.

 

[reefman]

i thought all the refractos r ATC (automatic temperature compensating)

 

[alrha]

i thought all the refractos r ATC (automatic temperature compensating)

i dont think all, but more of the better ones are.
either way to calibrate it, one would have to know the temp at calibration.

 

[pecan2phat]

Why do you think you need to cover the entire area of the glass with water?

2 drops dead center is all you need, go for 3 if your unsure.

 

[alrha]

Why do you think you need to cover the entire area of the glass with water?

thats what the instruction show.
it says if there is air in the middle, or if it is not fully covered its no good.

 

[pecan2phat]

That's new to me, maybe some other old timers can chime in on this issue.

 

[alrha]

yup, that why i posted, was wondering if it really makes a dif, or if the intructions are just being picky.