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Hydrometer is off

So I decided to test my hydrometer for accuracy in water this weekend. It read 1.002 in water. It made me wonder how long it’s been “off”. I ordered a one of the $20 “lab grade” ones from NB hoping it’s of better quality.

I did notice the wax at the bottom of the hydrometer had shifted and allowed for the pellets to move around and shift. Would this be the cause of the inaccuracy or is the wax just to prevent the pellets from flying all over the inside of the hydrometer?

I always figured the wax was to keep the buckshot level so the hydrometer floated straight. Just a guess though.

Technically hydrometers should be “zeroed” in 60° distilled water for perfect accuracy. Then you can adjust your readings up or down by the amount it is off. It seems like five different hydrometers give five different readings just like thermometers.

[quote=“HD4Mark”]I always figured the wax was to keep the buckshot level so the hydrometer floated straight. Just a guess though.

Technically hydrometers should be “zeroed” in 60° distilled water for perfect accuracy. Then you can adjust your readings up or down by the amount it is off. It seems like five different hydrometers give five different readings just like thermometers.[/quote]

Yeah I didn’t use distilled water so not sure if this would account for the discrepancy. I’ve been eyeballing the $20 one for a while not. Mostly cause it appears to be much easier to read. My current hydrometer has really small graduations and each line is 0.002 so it’s not very precise.

If you let your hydrometer “thunk” to the bottom of the tube, or allow it to receive any trauma to either end, the paper scale inside is quite capable of shifting up or down.

Suggest putting a permanent ink marker “mark” at the 0 line so you will know if this has occurred in the future.

I recommend getting a refractometer. Maybe I just have bad luck, but after buying three different hydrometers that gave unreliable readings, I figured I’d spent more than I had saved. It does have its eccentricities, but I highly recommend using this as an excuse to make the switch.

[quote=“mattnaik”]So I decided to test my hydrometer for accuracy in water this weekend. It read 1.002 in water. It made me wonder how long it’s been “off”. I ordered a one of the $20 “lab grade” ones from NB hoping it’s of better quality.

I did notice the wax at the bottom of the hydrometer had shifted and allowed for the pellets to move around and shift. Would this be the cause of the inaccuracy or is the wax just to prevent the pellets from flying all over the inside of the hydrometer?[/quote]

are you using temperature accuratly? they are calibrated to different temps. I have had some that are at 60 or 62 and some at 68

[quote=“grainbelt”][quote=“mattnaik”]So I decided to test my hydrometer for accuracy in water this weekend. It read 1.002 in water. It made me wonder how long it’s been “off”. I ordered a one of the $20 “lab grade” ones from NB hoping it’s of better quality.

I did notice the wax at the bottom of the hydrometer had shifted and allowed for the pellets to move around and shift. Would this be the cause of the inaccuracy or is the wax just to prevent the pellets from flying all over the inside of the hydrometer?[/quote]

are you using temperature accuratly? they are calibrated to different temps. I have had some that are at 60 or 62 and some at 68[/quote]

I just assumed they were all calibrated to 68. I didn’t receive any manual or instructions when i got it however long ago. It was this one here:

[quote=“mattnaik”][quote=“grainbelt”][quote=“mattnaik”]So I decided to test my hydrometer for accuracy in water this weekend. It read 1.002 in water. It made me wonder how long it’s been “off”. I ordered a one of the $20 “lab grade” ones from NB hoping it’s of better quality.

I did notice the wax at the bottom of the hydrometer had shifted and allowed for the pellets to move around and shift. Would this be the cause of the inaccuracy or is the wax just to prevent the pellets from flying all over the inside of the hydrometer?[/quote]

are you using temperature accuratly? they are calibrated to different temps. I have had some that are at 60 or 62 and some at 68[/quote]

I just assumed they were all calibrated to 68. I didn’t receive any manual or instructions when i got it however long ago. It was this one here:

[/quote]

most of mine are at 60 or 62 Cant remember which one it is ( I have had two that were at 68)

That 6 or 8 degree swing is probably your errors

The calibration temp will be on the paper inside the hydrometer - in very small print.

it usually comes with a sheet with the conversion rates to

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