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Miscellaneous Debris => Tech Corner => Topic started by: JayW on January 18, 2020, 02:38:58 PM

Title: Calibrating spirit thermometer using water softener water
Post by: JayW on January 18, 2020, 02:38:58 PM
I'm calibrating a really cheap red spirit thermometer in order to calibrate my (Ambient Weather) temperature sensors. Freezing water showed 28°F on the spirit thermometer, which would mean I would need to apply a 4°F correction.

Then it occurred to me that salts in water make water freeze at a lower temperature, and our water softener should yield water with salt ions. Is there enough there to make a difference in a cheap spirit thermometer? (I can see the small thermometer gradations to about 1°F accuracy, and certainly not a fraction of a degree.)

Do I need a salt correction to my calibration?
Title: Re: Calibrating spirit thermometer using water softener water
Post by: davidmc36 on January 18, 2020, 04:19:28 PM
If I could taste it and ice cubes were "punky" there must be an effect. Changed to RO water and modern softener and cubes are hard and clear. "White" ice before.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: ValentineWeather on January 18, 2020, 04:38:34 PM
You don't have a drinking water faucet with some kind of filtration like reverse osmosis? Most soft water systems I've been around do.  You can use bottled water if not sure.   
Title: Re: Calibrating spirit thermometer using water softener water
Post by: JayW on January 18, 2020, 06:08:37 PM
You don't have a drinking water faucet with some kind of filtration like reverse osmosis? Most soft water systems I've been around do.  You can use bottled water if not sure.   
And @davidmc36 no, I don't have a reverse osmosis in the system, yet - it's just straight softened water.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: CW2274 on January 18, 2020, 06:19:09 PM
Then it occurred to me that salts in water make water freeze at a lower temperature, and our water softener should yield water with salt ions. Is there enough there to make a difference in a cheap spirit thermometer?
Do I need a salt correction to my calibration?
I'd certainly think so. Personally I'd get some distilled water, freeze some, then crushing it to make a sludgy distilled ice/water mixture should make for about a 32.5F temp.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: JayW on January 18, 2020, 08:06:56 PM
Then it occurred to me that salts in water make water freeze at a lower temperature, and our water softener should yield water with salt ions. Is there enough there to make a difference in a cheap spirit thermometer?
Do I need a salt correction to my calibration?
I'd certainly think so. Personally I'd get some distilled water, freeze some, then crushing it to make a sludgy distilled ice/water mixture should make for about a 32.5F temp.
Thanks, I'll redo the test with distilled water.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: CW2274 on January 18, 2020, 08:57:46 PM
I guess I should have said slushy instead of sludgy... :roll:
Title: Re: Calibrating spirit thermometer using water softener water
Post by: the beteljuice on January 18, 2020, 09:14:29 PM
If you do any home brewing, you could always use the hygrometer to check the SG.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: galfert on January 18, 2020, 11:22:16 PM
A water softener does not make water salty. A water softener does not add salt to your water. The salt is used only to regenerate the resin beads (at set intervals) so that these resin beads can later be used in the ion exchange process to soften the water as the water is used at end points (faucets, dishwasher, washing machine, etc). When the salt brine solution is made during the regeneration process the last step is to fully rinse all the remaining salt out (the salt that remains that didn't give up ions to the beads) . The softening process when consuming water at end points replaces calcium and magnesium ions for sodium ions by these beads. The beads now full of just sodium ions (when freshly regenerate) get swapped out so that the calcium and magnesium are the ones that end up stuck to the breads as the beads give up the sodium. Sodium is not salt. Sodium is only half of what makes up salt, as salt is sodium chloride (NaCl). Since there is no chloride, there is no salt in your water. Yes the salt is the source of the sodium, but realize that you lost the other half of what constitutes salt during the process. People with high blood pressure or other heath concerns are told to limit salt intake not because of the entire salt molecules but rather just because of the sodium part of what is salt. Therefore these people have the same concern with water softeners as they are putting in sodium into the water. But there is an alternative for these people to soften the water a different way, as they can use Potassium Chloride instead of salt. The potassium ion is then used in the system instead of the sodium ion and it works but isn't as efficient as sodium chloride (salt).

Regardless, hard water with calcium and magnesium versus soft water with sodium (or potassium) is not adequate for any scientific purpose. Destiled water or reverse osmosis water would yield better results.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: JayW on January 19, 2020, 07:50:19 AM
A water softener does not make water salty. A water softener does not add salt to your water. The salt is used only to regenerate the resin beads (at set intervals) so that these resin beads can later be used in the ion exchange process to soften the water as the water is used at end points (faucets, dishwasher, washing machine, etc). When the salt brine solution is made during the regeneration process the last step is to fully rinse all the remaining salt out (the salt that remains that didn't give up ions to the beads) . The softening process when consuming water at end points replaces calcium and magnesium ions for sodium ions by these beads. The beads now full of just sodium ions (when freshly regenerate) get swapped out so that the calcium and magnesium are the ones that end up stuck to the breads as the beads give up the sodium. Sodium is not salt. Sodium is only half of what makes up salt, as salt is sodium chloride (NaCl). Since there is no chloride, there is no salt in your water. Yes the salt is the source of the sodium, but realize that you lost the other half of what constitutes salt during the process. People with high blood pressure or other heath concerns are told to limit salt intake not because of the entire salt molecules but rather just because of the sodium part of what is salt. Therefore these people have the same concern with water softeners as they are putting in sodium into the water. But there is an alternative for these people to soften the water a different way, as they can use Potassium Chloride instead of salt. The potassium ion is then used in the system instead of the sodium ion and it works but isn't as efficient as sodium chloride (salt).

Regardless, hard water with calcium and magnesium versus soft water with sodium (or potassium) is not adequate for any scientific purpose. Destiled water or reverse osmosis water would yield better results.
Thanks for clearing that up.
Title: Re: Calibrating spirit thermometer using water softener water
Post by: DaleReid on January 19, 2020, 09:20:26 AM
I've learned a lot here.

I also looked briefly at the formula for depression of freezing due to solutes and it would take a pretty nasty tasting solution to depress the temp very much.

I'm wondering when high precision thermometers are made, like the old mercury Taylors and stuff, if they etch the values on the glass column after they test them, or hope the manufacturing process was close enough?

There are some max/min setups most often in a Stephenson (sp?) shield that are set at slight angles from the horizontal and I think that they were mercury filled.  Yet how did they get them to be accurate across the range? 
Title: Re: Calibrating spirit thermometer using water softener water
Post by: ValentineWeather on January 19, 2020, 12:48:53 PM
I've learned a lot here.

I also looked briefly at the formula for depression of freezing due to solutes and it would take a pretty nasty tasting solution to depress the temp very much.

I'm wondering when high precision thermometers are made, like the old mercury Taylors and stuff, if they etch the values on the glass column after they test them, or hope the manufacturing process was close enough?

There are some max/min setups most often in a Stephenson (sp?) shield that are set at slight angles from the horizontal and I think that they were mercury filled.  Yet how did they get them to be accurate across the range?

I had a set of these, still do have the Townsend support it allows you to twirl the max to reset and properly adjust the minimum tilt. 
The minimum has a small index inside that is forced down as the temperature drops to record the low temp.

This is very old school. Accuracy is (+/- ) .5C  or (+/-) .9F.
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