Salinity problem

[BayBud]

Ok I have a problem.

I recently bought an aqua-medic salinity meter because i was fed up with needing to calibrate my refractometer every few days.

I have calibrated the meter and the source sample reads 1.026 as it should.

I put a drop on my refractometer and exactly the same reading.

Here is the problem.

meter says tank is 1.024 refractometer says 1.029!

What do i trust? if anyone has any knowledge on the aquamedic salinity meter please please tell me if you have had a similar problem.

thanks all.

[Jason McKenzie]

Was the calibration fluid heated to your tank temp?

J

[BayBud]

no it wasn't, the instructions nothing like that. Shall i try this?

[BayBud]

Hi Jason, i just tested the samples temp and it was within .5 deg C of the tank, is this enough to cause a difference in reading like that?

[Jason McKenzie]

SG is dependent on temp. I would try adjusting you calibration fluid to the same temp as your water. And use it to calibrate your Refractometer.

Most Refractometers are actually designed for the wine industry. They are factory calibrated for much lower temps and much lower SG

J

[BayBud]

Originally Posted by Jason McKenzie

SG is dependent on temp. I would try adjusting you calibration fluid to the same temp as your water. And use it to calibrate your Refractometer.

Most Refractometers are actually designed for the wine industry. They are factory calibrated for much lower temps and much lower SG

J

I just had a thought Jason. I do have a skimmer which is still running itself in. There are a few (not loads) but a few micro bubbles around.

Could this be causing a problem with the meters ability to measure the resistance, or whatever it does?

thanks for your help, im getting so panicky now with the Tubastrea in there.

[BayBud]

Originally Posted by Jason McKenzie

SG is dependent on temp. I would try adjusting you calibration fluid to the same temp as your water. And use it to calibrate your Refractometer.

Most Refractometers are actually designed for the wine industry. They are factory calibrated for much lower temps and much lower SG

J

im gonna do that right now thanks!

[BayBud]

sorry to keep posting.

I just had another thought, if i warm the calibration fluid up that .5 deg C it's going to equalize to the temperature of the refractometer as soon as it touches it.