jthomas0385
Member
How do you recalibrate a refractometer?? How often should this be done?
Refractometer Recalibration
- Thread starter jthomas0385
- Start date
locoyo386
Member
Hi there,
Well this is not easy. Calibrating anything requires a datum or reference point. For example, if you use RO/DI water the assumption would be that the SG is 1.000. You could than calibrate the RM for this value. Place the water in the lence and set the level to 1.000. Once this is done the RM will read all SG values againts this set value. The problem with that is that the further you go from this value the more you will accumulate the erro (most of the time +- .001). A value that reads at 1.025 might have accumulated more error than a value of 1.002. Thus it is recomended to have a solution that you moreless know what the SG value is (in reality this is hard to do, thus adding to the margin of error of the RM). That is why RO/DI water is used, it will have the closest value to 1.000 than other liquids. Also note that to be more accurate for a greater value of SG, you would have to use a solution (for calibrating the RM) that has a more accurate value to be tested (if you want to test for an SG of 1.025, than you should use a solution that has this value).
Well this is not easy. Calibrating anything requires a datum or reference point. For example, if you use RO/DI water the assumption would be that the SG is 1.000. You could than calibrate the RM for this value. Place the water in the lence and set the level to 1.000. Once this is done the RM will read all SG values againts this set value. The problem with that is that the further you go from this value the more you will accumulate the erro (most of the time +- .001). A value that reads at 1.025 might have accumulated more error than a value of 1.002. Thus it is recomended to have a solution that you moreless know what the SG value is (in reality this is hard to do, thus adding to the margin of error of the RM). That is why RO/DI water is used, it will have the closest value to 1.000 than other liquids. Also note that to be more accurate for a greater value of SG, you would have to use a solution (for calibrating the RM) that has a more accurate value to be tested (if you want to test for an SG of 1.025, than you should use a solution that has this value).
locoyo386
Member
Originally Posted by JThomas0385
http:///forum/post/2902140
How do you recalibrate a refractometer?? Place a liquid solution with a know SG (exp, RO or DI) on the lence and set it to that value)
How often should this be done?It depends. For example if you are goint to do hyposalinity, than I would recomend you recalibrate the RM with RO/DI. If you are going test salinity say at 1.025, than I would calibrate it twice a year with a know SG of 1.025
Hope this helps.
http:///forum/post/2902140
How do you recalibrate a refractometer?? Place a liquid solution with a know SG (exp, RO or DI) on the lence and set it to that value)
How often should this be done?It depends. For example if you are goint to do hyposalinity, than I would recomend you recalibrate the RM with RO/DI. If you are going test salinity say at 1.025, than I would calibrate it twice a year with a know SG of 1.025
Hope this helps.
florida joe
Well-Known Member
Ummm call me crazy but ro water has a salinity of Zero. Most refractometers are calibrated at 68 degrees F so take some RO water put it in your refrigerator for a while take it out put a instant read thermometer in it when the water gets to 68 degrees put it on the window of your refractometer and adjust the read line to zero.
Then again I am crazy Joe
Then again I am crazy Joe
locoyo386
Member
Originally Posted by florida joe
http:///forum/post/2902313
Ummm call me crazy but ro water has a salinity of Zero. Most refractometers are calibrated at 68 degrees F so take some RO water put it in your refrigerator for a while take it out put a instant read thermometer in it when the water gets to 68 degrees put it on the window of your refractometer and adjust the read line to zero.
Then again I am crazy Joe
Does this mean that the reading should be done at a temperature of 68 degrees F(of the lwater) or just the calibration?
http:///forum/post/2902313
Ummm call me crazy but ro water has a salinity of Zero. Most refractometers are calibrated at 68 degrees F so take some RO water put it in your refrigerator for a while take it out put a instant read thermometer in it when the water gets to 68 degrees put it on the window of your refractometer and adjust the read line to zero.
Then again I am crazy Joe
Does this mean that the reading should be done at a temperature of 68 degrees F(of the lwater) or just the calibration?
florida joe
Well-Known Member
Just the calibration your refractometer should compensate for your tank water temp after your initial calibration
florida joe
Well-Known Member
Originally Posted by locoyo386
http:///forum/post/2902341
Are the salt refractormeter pre-calibrated?
most are just check by using the method i stated above it should read zero with distilled water at 68 f and a refractometer is a refractometer not salt water Specific Bouncing around in shipment can throw them off
http:///forum/post/2902341
Are the salt refractormeter pre-calibrated?
most are just check by using the method i stated above it should read zero with distilled water at 68 f and a refractometer is a refractometer not salt water Specific Bouncing around in shipment can throw them off
jthomas0385
Member
My refreactometer is about 6 months old. The LFS I bought it from told me it should be recalibrated every 3 months or so.... I think thats what they said anyway.
florida joe
Well-Known Member
Originally Posted by JThomas0385
http:///forum/post/2902350
My refreactometer is about 6 months old. The LFS I bought it from told me it should be recalibrated every 3 months or so.... I think thats what they said anyway.
its no big deal just do as i suggest if you trust me that is
http:///forum/post/2902350
My refreactometer is about 6 months old. The LFS I bought it from told me it should be recalibrated every 3 months or so.... I think thats what they said anyway.
its no big deal just do as i suggest if you trust me that is
jthomas0385
Member
Will do. Thank you for the help.
florida joe
Well-Known Member
florida joe
Well-Known Member
Originally Posted by camfish
http:///forum/post/2902566
Yeah man. Joe helped me calibrate my refractometer too lol! That was a LONG time ago though. Thanks again man.
Yea you young wipper snappers need all the help you can get
saltygerman
Member
Originally Posted by florida joe
http:///forum/post/2903003
Yea you young wipper snappers need all the help you can get
Ok being as I always have to overthink things...here we go. I just got my RO/DI unit I also have a water softener. Will the salt in my water supply throw off my Refractor calibration or does the RO/DI filter all this out?
http:///forum/post/2903003
Yea you young wipper snappers need all the help you can get
Ok being as I always have to overthink things...here we go. I just got my RO/DI unit I also have a water softener. Will the salt in my water supply throw off my Refractor calibration or does the RO/DI filter all this out?
C
cmaxwell39
Guest
Your Ro unit will take out everything including anything that your water softner leaves in the water.
bang guy
Moderator
Originally Posted by florida joe
http:///forum/post/2902313
Ummm call me crazy but ro water has a salinity of Zero. Most refractometers are calibrated at 68 degrees F so take some RO water put it in your refrigerator for a while take it out put a instant read thermometer in it when the water gets to 68 degrees put it on the window of your refractometer and adjust the read line to zero.
Then again I am crazy Joe
Hey there Crazy Joe
The temperature of the water being tested isn't relevant. What you actually need to do if you want to calibrate at 68F is get the temperature of the refractometer to 68, not the test water. I believe it is advisable to test using the device at room temp though.
The ideal calibration would be to use 35ppt calibration fluid with the refractometer at the temperature it would normally be when testing your tank water. I caution against storing the refractometer near a heat source because the reading will be unpredictible. For example, I have seen quite a few people store their refracometer on top of a hot canopy.
As far as Salinity of RO being zero, this is absolutely true. I just want to mention that some hobbiests incorrectly use the S.G. scale and that side would read 1.00 with RO water. You are correct in that since Refractometers do not measure Specific Gravity it is the Salinity scale that should be used "0/000".
http:///forum/post/2902313
Ummm call me crazy but ro water has a salinity of Zero. Most refractometers are calibrated at 68 degrees F so take some RO water put it in your refrigerator for a while take it out put a instant read thermometer in it when the water gets to 68 degrees put it on the window of your refractometer and adjust the read line to zero.
Then again I am crazy Joe
Hey there Crazy Joe
The temperature of the water being tested isn't relevant. What you actually need to do if you want to calibrate at 68F is get the temperature of the refractometer to 68, not the test water. I believe it is advisable to test using the device at room temp though.
The ideal calibration would be to use 35ppt calibration fluid with the refractometer at the temperature it would normally be when testing your tank water. I caution against storing the refractometer near a heat source because the reading will be unpredictible. For example, I have seen quite a few people store their refracometer on top of a hot canopy.
As far as Salinity of RO being zero, this is absolutely true. I just want to mention that some hobbiests incorrectly use the S.G. scale and that side would read 1.00 with RO water. You are correct in that since Refractometers do not measure Specific Gravity it is the Salinity scale that should be used "0/000".
florida joe
Well-Known Member
Originally Posted by Bang Guy
http:///forum/post/2903073
Hey there Crazy Joe
The temperature of the water being tested isn't relevant. What you actually need to do if you want to calibrate at 68F is get the temperature of the refractometer to 68, not the test water. I believe it is advisable to test using the device at room temp though.
The ideal calibration would be to use 35ppt calibration fluid with the refractometer at the temperature it would normally be when testing your tank water. I caution against storing the refractometer near a heat source because the reading will be unpredictible. For example, I have seen quite a few people store their refracometer on top of a hot canopy.
As far as Salinity of RO being zero, this is absolutely true. I just want to mention that some hobbiests incorrectly use the S.G. scale and that side would read 1.00 with RO water. You are correct in that since Refractometers do not measure Specific Gravity it is the Salinity scale that should be used "0/000".
Not so sure Bang, the temperature of your water is not relevant if you have a refractometer with temperature compensation. (Which most are). If as you say the refractometer was calibrated at 68 f and I had distilled water at 68 f it should read zero. If not recalibration is called for Is it not easier to bring the water to 68 f then the refractometer?
http:///forum/post/2903073
Hey there Crazy Joe
The temperature of the water being tested isn't relevant. What you actually need to do if you want to calibrate at 68F is get the temperature of the refractometer to 68, not the test water. I believe it is advisable to test using the device at room temp though.
The ideal calibration would be to use 35ppt calibration fluid with the refractometer at the temperature it would normally be when testing your tank water. I caution against storing the refractometer near a heat source because the reading will be unpredictible. For example, I have seen quite a few people store their refracometer on top of a hot canopy.
As far as Salinity of RO being zero, this is absolutely true. I just want to mention that some hobbiests incorrectly use the S.G. scale and that side would read 1.00 with RO water. You are correct in that since Refractometers do not measure Specific Gravity it is the Salinity scale that should be used "0/000".
Not so sure Bang, the temperature of your water is not relevant if you have a refractometer with temperature compensation. (Which most are). If as you say the refractometer was calibrated at 68 f and I had distilled water at 68 f it should read zero. If not recalibration is called for Is it not easier to bring the water to 68 f then the refractometer?