Refractometer Standard

[Scarbird]

Good Morning All,

Great swap yesterday!
Has anyone else tested the refractometer standard? It says 1.026 but
my Sybon Opticon FG100sa reads the standard as 1.027.
I haven't had to recalibrate since purchased a few years ago.
The manufacturer supplied calibration standard which is 1.0 tests perfect.
Why would the standard provided at yesterday's swap test at 1.027?
Can some others check the standard and weigh in on this?

Regards,

John

 

[Coral reefer]

Make sure your refractometer and the standard are at the correct (normal tank) temp.

 

[BAYMAC]

Put refract, standard and a little bag of water in you pocket for a few minutes

 

[zeroinverse]

Hahahaha! Just don't pop the bag or people will think you pee'd in your pants, or did something funny with things in your pockets.

 

[aqua-nut]

I thought these refractometers were 'temperature compensating'.

The refractometer body warms/cools the sample to match it at (usually) room temp. If you calibrate at room temp it should all work out. I just sampled some water I have mixing outside, temp below 60F. Within a few seconds the SG stabilizes. I take this to mean the mass of the refractometer has warmed the 3-4 drops of sample to it's room temp and is ready for a reading.

I don't trust my pocket to be the same consistent temp. Sometimes I've got 'hot pockets', sometimes not so hot!

 

[Scarbird]

Yes my refractometer is supposedly ATC(automatic temperature compensation).
On any day, my aquarium sample increases slightly after sitting on the refractometer for around 30 sec.
Both samples were at room temperature at the time of testing, one was at 1.0 as advertised, the other at 1.027 advertised at 1.026.
Has anyone else tested the 1.026 standard?

 

[pinner]

I tested the standards on my Hana refract and read 1.026. I didnt warm up or anything just put some on and read 1.026 or 35

 

[Scarbird]

Thanks everyone, I guess its time to recalibrate my refractometer!
Also, thanks to BAR for providing the standard.

 

[lattehiatus]

Put refract, standard and a little bag of water in you pocket for a few minutes

Hahahaha! Just don't pop the bag or people will think you pee'd in your pants, or did something funny with things in your pockets.

I don't trust my pocket to be the same consistent temp. Sometimes I've got 'hot pockets', sometimes not so hot!

Not a single "Is that a refractometer in your pocket or are you just happy to see me?" comment?!? We are slipping! :bigsmile:

@ Scarbird: I am impressed that your refractometer has not needed to be calibrated in so many years! Some time ago I had a terrible refractometer that needed to be calibrated even between readings taken two minutes apart - needless to say it is junk, but the refractometer made me dubious of every salinity measurement. I even purchased (and promptly broke) one of the massive Tropic Marin hydrometers in an attempt to double- and triple-check my readings against known standards.

If you feel like driving yourself a little batty, Randy Holmes Farley has an excellent article about refractometers and measuring salinity.

 

[Scarbird]

Put refract, standard and a little bag of water in you pocket for a few minutes

Hahahaha! Just don't pop the bag or people will think you pee'd in your pants, or did something funny with things in your pockets.

I don't trust my pocket to be the same consistent temp. Sometimes I've got 'hot pockets', sometimes not so hot!

Not a single "Is that a refractometer in your pocket or are you just happy to see me?" comment?!? We are slipping! :bigsmile:

@ Scarbird: I am impressed that your refractometer has not needed to be calibrated in so many years! Some time ago I had a terrible refractometer that needed to be calibrated even between readings taken two minutes apart - needless to say it is junk, but the refractometer made me dubious of every salinity measurement. I even purchased (and promptly broke) one of the massive Tropic Marin hydrometers in an attempt to double- and triple-check my readings against known standards.

If you feel like driving yourself a little batty, Randy Holmes Farley has an excellent article about refractometers and measuring salinity.

Thanks David, Ill check it out. As for needing recalibrating, apparently
I should have done this long ago!

 

[Coral reefer]

Are you off much? I've had one a couple years that I checked many times and was never really off more than .001 which I usually call good enough for me work

 

[Scarbird]

Are you off much? I've had one a couple years that I checked many times and was never really off more than .001 which I usually call good enough for me work

Mine is high by exactly .001

 

[aqua-nut]

Are you off much? I've had one a couple years that I checked many times and was never really off more than .001 which I usually call good enough for me work

Mine is high by exactly .001

The important point here is, is that significant?

 

[Scarbird]

Agreed,
My target has been 1.026 so Im actually @ 1.025, no big deal.
It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

 

[rygh]

Are you off much? I've had one a couple years that I checked many times and was never really off more than .001 which I usually call good enough for me work

Mine is high by exactly .001

The important point here is, is that significant?

Seawater can technically vary from 30 to 38.
Although for coral locations it is far less. Red sea is pretty high though.
So unless you made sure all your livestock is from the same place, then matched that place,
the odds are your current level is a bit off from "natural" for something in your tank.

More important is to double check when you buy something.
Make sure your tank and water in bag is not way off, or extend acclimation.

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

 

[lattehiatus]

It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

Not at this time, unfortunately! It takes quite a bit of labor and time to prepare the standards, but it is possible we can get all types of standards with more help! Which other standards are you most interested in having?

 

[Scarbird]

It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

Not at this time, unfortunately! It takes quite a bit of labor and time to prepare the standards, but it is possible we can get all types of standards with more help! Which other standards are you most interested in having?

It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

Not at this time, unfortunately! It takes quite a bit of labor and time to prepare the standards, but it is possible we can get all types of standards with more help! Which other standards are you most interested in having?

I suppose over time pH, Ca and Mg would be nice. I am wondering how far off my other test kits are. If a person were to, as Denzil suggested, use all digital tests kits then the standards would be a great way to keep the kits adjusted properly.
Incidently, how were we fortunate enough to aquire those we already have? :glasses:

 

[lattehiatus]

It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

Not at this time, unfortunately! It takes quite a bit of labor and time to prepare the standards, but it is possible we can get all types of standards with more help! Which other standards are you most interested in having?

I suppose over time pH, Ca and Mg would be nice. I am wondering how far off my other test kits are. If a person were to, as Denzil suggested, use all digital tests kits then the standards would be a great way to keep the kits adjusted properly.
Incidently, how were we fortunate enough to aquire those we already have? :glasses:

pH standard will probably not have much of a shelf life, but fortunately the pH calibration fluids that come packed in mylar bags are readily available.
Ca and Mg could be quite simple, will have to look into that!
PO4/phosphate and NO3/nitrate would probably be easy to make as well.

One way we could potentially do this is instead of having individual little bottles of standards, large bottles of standards could be made available at BAR meetings so you can test your kit on the spot.

The dips/standards at the swap were prepared and packaged by the swap planners.

 

[BAYMAC]

It is nice to have these lab grade standards though. I dont know if after another year or two the error would continue to creep up.
Do we have more types of these standards available?

Not at this time, unfortunately! It takes quite a bit of labor and time to prepare the standards, but it is possible we can get all types of standards with more help! Which other standards are you most interested in having?

I suppose over time pH, Ca and Mg would be nice. I am wondering how far off my other test kits are. If a person were to, as Denzil suggested, use all digital tests kits then the standards would be a great way to keep the kits adjusted properly.
Incidently, how were we fortunate enough to aquire those we already have? :glasses:

pH standard will probably not have much of a shelf life, but fortunately the pH calibration fluids that come packed in mylar bags are readily available.
Ca and Mg could be quite simple, will have to look into that!
PO4/phosphate and NO3/nitrate would probably be easy to make as well.

One way we could potentially do this is instead of having individual little bottles of standards, large bottles of standards could be made available at BAR meetings so you can test your kit on the spot.

The dips/standards at the swap were prepared and packaged by the swap planners.

pH calibration standards have ~90 days of opened bottle shelf life and ~2 years unopened, but they do very from standard to standard ( IE. higher ones IIRC have less of a shelf life due to CO2).

We make our own here at RMI and we only do it like once a year given the shelf life.

 

[Vincerama2]

The label on the standard says something like "1.026 or 35 ppm" (Or whatever, I don't have it here).

I went to calibrate my refractometer and noticed that my 1.026 does not match up with the 35ppm (or whatever)!!

So I'm thinking ... Ugh, I guess just pick one or the other! So I chose 1.026.

To be very honest, I keep my tank "around" 1.025 plus or minus A LOT because I'm lazy and sort of just let the salinity of my water changes drift a bit one way or the other.