Salt Test --- My Hygros are nuts

0 That Guy 00 That Guy 0 Posts: 188
I have two digital hygrometers. One I purchased when I got my humidor and the other is an Oregon Scientific weather station hygro. Someone had asked me in my previous thread if they were calibrated correctly but I had just calibrated my 2nd one to match my Oregon Scientific.

So I broke the ol salt test out to test them both. The new hygro read 74% so I marked it as one low. The Oregon Sci. read 72% so I was incorrect in thinking that it was reading right and marked it as 3 low.

Now here's where it gets weird. Since reseasoning my humi I have, for the first time, had some trouble getting the RH to come down (earlier I couldn't get it to stay up) as it was climbing up around 75-77%. So I would just open and close the lid, airing it out, periodically throughout the day until the RH dropped to 60%. Upon shutting it, the RH would start to climb again - it's not a bad problem to have though as I use beads which have started working now.

Anywho.......Both hygros set over night and this morning the new one read 72% which is marked as one low but the Oregon Scientific reads 65%, which is only supposed to be 3 low. How the heck to I make sense of 7% difference? On a side note I am using 65% beads.

Comments

  • xmacroxmacro Posts: 3,402
    Even digital hygros can be a bit weird. I've got 2 - the first one calibrated perfectly with no problems. But when I bought the second one, it wouldn't really calibrate - it read 75% after the first salt test, then it read 73% when I re-checked it (oh, BTW - it constantly reads the temperature about 2F below what I know it is) Eventually I put both hygrometers into the same bag and salt-tested them both until they consistently read 75%, then put them both in the same humidor as a triple-check. They work now, but the second one still reads an incorrect temperature.
  • madurofanmadurofan Posts: 6,152
    First off don't use a bag, use a piece of tupperware. Second but them somewhere in the house where the temp will not fluctuate.

    Also remember this is Relative Humidity, which is Relative to the temperature. So if you do your salt test somewhere where the temp is 75* then put the hygro in a humidor that is 65*. You could potentially have issues.
  • adamkhaliladamkhalil Posts: 80
    0 That Guy 0:
    On a side note I am using 65% beads.
    I'm surprised you're having trouble! I just got my heartfelt last week and i dropped from 73'ish range down to a perfect 65 (i have 65 beads as well). I barely need the hygrometer anymore!
  • xmacroxmacro Posts: 3,402
    madurofan:
    First off don't use a bag, use a piece of tupperware. Second but them somewhere in the house where the temp will not fluctuate.

    Also remember this is Relative Humidity, which is Relative to the temperature. So if you do your salt test somewhere where the temp is 75* then put the hygro in a humidor that is 65*. You could potentially have issues.
    I'm not sure that's right - because the humidity is relative, that means it's relative to temperature. So that means if your hygro reads 65%, then it's 65% of whatever the temp is (so it should read 65% regardless of the temperature). This means that your hygro shouldn't change depending on the temp (if it does, then it should quickly come back down).

    Now, if the hygro was a measure of absolute humidity, THEN the humidity would fluctuate with the temperature because it's measuring humidity against an absolute standard instead of comparing it to whatever the temperature is, instead of being relative to temperature
    .
  • madurofanmadurofan Posts: 6,152
    xmacro:
    madurofan:
    First off don't use a bag, use a piece of tupperware. Second but them somewhere in the house where the temp will not fluctuate.

    Also remember this is Relative Humidity, which is Relative to the temperature. So if you do your salt test somewhere where the temp is 75* then put the hygro in a humidor that is 65*. You could potentially have issues.
    I'm not sure that's right - because the humidity is relative, that means it's relative to temperature. So that means if your hygro reads 65%, then it's 65% of whatever the temp is. This means that your hygro shouldn't change depending on the temp (if it does, then it should quickly come back down).

    Now, if the hygro was a measure of absolute humidity, THEN the humidity would fluctuate with the temperature
    .
    HAHAHA. I was waiting for kuzi to pop in and correct that. You beat him to it. In theory what you said is correct. In practive however,I have found that it is better to calibrate the hygro inside my wine fridge. It does not scientifically make sense that I know of but it has worked well for me in practice.
  • 0 That Guy 00 That Guy 0 Posts: 188
    I can't begin to break it down like my man xmacro just did but everything I'm doing to test is in the same room under the exact same conditions as my humidor. The difference this time with the humidity climbing is that I reseasoned and probably over seasoned my humi hints the reason the RH continues to go up. I have however gotten it under control but in order to get it down I had to dry my beads out completely. I'm testing both of my hygros again in the same zip lock and now placed them inside tupperware as well so I can test the readings against one another and go figure they both read 72%. Absolute craziness!
  • kuzi16kuzi16 Posts: 14,616 ✭✭✭
    madurofan:
    xmacro:
    madurofan:
    First off don't use a bag, use a piece of tupperware. Second but them somewhere in the house where the temp will not fluctuate.

    Also remember this is Relative Humidity, which is Relative to the temperature. So if you do your salt test somewhere where the temp is 75* then put the hygro in a humidor that is 65*. You could potentially have issues.
    I'm not sure that's right - because the humidity is relative, that means it's relative to temperature. So that means if your hygro reads 65%, then it's 65% of whatever the temp is. This means that your hygro shouldn't change depending on the temp (if it does, then it should quickly come back down).

    Now, if the hygro was a measure of absolute humidity, THEN the humidity would fluctuate with the temperature
    .
    HAHAHA. I was waiting for kuzi to pop in and correct that. You beat him to it. In theory what you said is correct. In practive however,I have found that it is better to calibrate the hygro inside my wine fridge. It does not scientifically make sense that I know of but it has worked well for me in practice.
    sorry. im too slow.
  • 0 That Guy 00 That Guy 0 Posts: 188
    June 16th breakdown:

    I've learned today that I will never understand my two Hygros and will just have to base my RH on an assumed percentage. I placed them both in the same ziplock in the same rubbermaid and did the salt test. They both read 75% on the dime this morning - it was glorious! I placed them back in the humidor and went out to make insurance calls. Upon returning the Oregon Scientific reads 65% (remember I have 65% beads) and my generic digital reads 70%.

    What have I learned from this experiment?
  • madurofanmadurofan Posts: 6,152
    0 That Guy 0:
    June 16th breakdown:

    I've learned today that I will never understand my two Hygros and will just have to base my RH on an assumed percentage. I placed them both in the same ziplock in the same rubbermaid and did the salt test. They both read 75% on the dime this morning - it was glorious! I placed them back in the humidor and went out to make insurance calls. Upon returning the Oregon Scientific reads 65% (remember I have 65% beads) and my generic digital reads 70%.

    What have I learned from this experiment?
    That you should give them 24 hours to stabilize before judging the results.
  • 0 That Guy 00 That Guy 0 Posts: 188
    Generic set for 24 - Oregon set for 12 - both read 75%
  • madurofanmadurofan Posts: 6,152
    I mean in your humi. Let them stabilize for 24 hours. I used to have a generic hygro, it was a little slower to catch up to the right rh. I called it the slow child, for that and other reasons.
  • 0 That Guy 00 That Guy 0 Posts: 188
    Oh ok I definitely misunderstood you then. Good call - I'll see what it looks like by tomorrow
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