Pinpoint Salinity Calibration Fluid Created Equal?

[JamesReef]

I cracked open a new bottle I purchased a year ago and tested it, I was getting some strange readings when using a no-name refractometer I purchased from BRS about that same time. So I purchased a new Sybon refractometer and another bottle of fluid just to be safe. Both fluids (the old from year ago and new purchased last week) are 53ms fluid solution from American Marine as labeled, both have the chart on the label of 53ms = 1.0264 @ SG 35.

 

But they don't read equal when using the Sybon refractometer. When I calibrate the new fluid to 35 to reach 1.0264ish (it was only very slightly off out of the box), the fluid I purchased a year ago reads around 1.0274 and 36ish.

 

Has anyone else noticed variations in this fluid?

[lakshwadeep]

Have you tested them in a conductivity meter?. They are specifically made for such meters (mS is millisiemens, with siemens being a unit of conductance.

[JamesReef]

I haven't. Hopefully DA will have their Salinity probe out sometime in the near future so I can have another testing option.

[J-Ranko]

I cracked open a new bottle I purchased a year ago and tested it, I was getting some strange readings when using a no-name refractometer I purchased from BRS about that same time. So I purchased a new Sybon refractometer and another bottle of fluid just to be safe. Both fluids (the old from year ago and new purchased last week) are 53ms fluid solution from American Marine as labeled, both have the chart on the label of 53ms = 1.0264 @ SG 35.

 

But they don't read equal when using the Sybon refractometer. When I calibrate the new fluid to 35 to reach 1.0264ish (it was only very slightly off out of the box), the fluid I purchased a year ago reads around 1.0274 and 36ish.

 

Has anyone else noticed variations in this fluid?

 

It could be due to evaporation from the older bottle. How was it stored, how long do you keep it open, and how much of it have you already used?

[Cheetos]

I've run into that in the past with the Pinpoint calibration fluid. I use it to calibrate both my refractometer and salinity meter. I had at one point three different bottles with different readings from each. According to people at Pinpoint they had some bad batches of calibration fluid and sent me 3 new bottles all reading the same on both instruments. I would pick up another bottle just to see if you get the same readings as the second bottle. If it is the same then your old bottle is probably just that....old!

[JamesReef]

I've run into that in the past with the Pinpoint calibration fluid. I use it to calibrate both my refractometer and salinity meter. I had at one point three different bottles with different readings from each. According to people at Pinpoint they had some bad batches of calibration fluid and sent me 3 new bottles all reading the same on both instruments. I would pick up another bottle just to see if you get the same readings as the second bottle. If it is the same then your old bottle is probably just that....old!

 

 

Ahh....ok thanks Cheetos, this could be what I am experiencing then. Both bottles were brand new, stored in my home at temps ranging from 70-75, well sealed. One was just a year older than the other.

 

I'll order another bottle.

 

Thanks!