Hygrometers... do any of them work? haha

Discussion in 'Incubating & Hatching Eggs' started by rickerra, Feb 3, 2011.

  1. rickerra

    rickerra Chillin' With My Peeps

    Jan 26, 2011
    Spokane, WA
    Hi Gang,
    So I made my own incubator and am now dialing in the humidity levels on it.

    My incubator is in my basement... which is a steady 58 degrees with around mid-40's RH% (Relative Humidity). I say "around" because I can't be certain. I have 3 different hygrometers and they are giving me whacky results.


    So a few days ago I put the white Springfield one and the larger Acurite one into a ziploc bag with a coffee cup of 1/2 cup salt and 1/4 cup water for 12 hours. This is the common method used to create a known 75% RH level inside the ziploc sealed bag so you can see how accurate your hydrometers are.
    > Springfield read 69% (so 6% low)
    > Acurite read 70% (so 5 % low)

    After I took them out, they equalized to room RH% but adding back their error margin gave me two different %'s... so I worried I did something wrong in the calibration test.

    So I bought the PetCo hygrometer... which folks said was pretty accurate.

    Last night I put them all into a new ziploc sealed bag for another round of calibration
    > Springfield read 69% (so still 6% low)
    > Acurite read 70% (so still 5% low)
    > PetCo read 77% (so 2% high)

    So the first two were at least consistent... and the PetCo one did seem pretty good right out of the box.

    So I take all three into the basement near my incubator and let them equalize to the basement temp/RH for over an hour. That is the picture you see above.

    If we factor in their margin of error determined from the calibration test, the readings they give would be:
    Springfield: 46% + 6% = 52%
    Acurite: 43% + 5% = 48%
    PetCo: 43% - 2% = 41%

    It does not appear that the margin of error scales evenly from the higher % range to the lower % range. If I just take them at face value and ignore the margin of error present from the calibration test... they look like they are all pretty much in the same ballpark. But when I account for the margin of error... they don't seem to match up. This bugs me! haha

    Thoughts? Thanks!

    **edited because I meant "hygrometer" not "hydrometer"... haha
    Last edited: Feb 3, 2011
  2. Lark Rise

    Lark Rise Chillin' With My Peeps

    Jan 22, 2011
    East Central Georgia
    I did almost like you did with 3 different hygrometers: Springfield, Fluker's and PETCO. Results were similar to yours and drove me nuts. I decided it was just easier for me to choose one brand, so went with 2 PETCOs in 2 incubators because they calibrated most accurately. Returned the Fluker's, kept the Springfield for the thermometer. Chicks hatched just great out of both incubators, so I think the PETCO has proven itself. [​IMG]
  3. rebelcowboysnb

    rebelcowboysnb Confederate Money Farm

    I would guess the room humidity is 50% Both digitals are within 2% of that when accounting for calibration. Well withing useable for incubation.... The other? Who knows? If you need more accuracy you can calibrate at that range.

    SODIUM CHLORIDE (table salt) 75.30%
  4. flyweed

    flyweed Chillin' With My Peeps

    Feb 12, 2009
    I have used a few different "digital" or dial type hygrometers (I assume you meant Hygrometer as you said Hydrometer in your thread title which is used to measure alcohol content)

    I have gotten rid of all my digital ones, as they just aren't accurate enough for me and Now I always use a wet bulb thermometer, it is dead on accurate.

  5. rickerra

    rickerra Chillin' With My Peeps

    Jan 26, 2011
    Spokane, WA
    Quote:[​IMG] Good catch! I do mean "hygrometer"! But "hydrometer" just sounds so right! haha

    Yeah... I'd like a nice web bulb. need to try the wet shoelace over the bulb idea.

  6. gumbii

    gumbii Chillin' With My Peeps

    Oct 7, 2010
    bell gardens, ca
    it's a lot of stress, but unnecessary stress... just choose one, and work with it... i use the petco one, calibrated to 76%... just put it in the incubator and don't worry about other readings because it's never gonna be perfect... that just means that for days 1-18 it will read 40% but with a possible error margin of -/+4% or so... witch is alright... on lock down, the same thing... the same with thermometers... those fancy digital ones just cause more stress for us... people before would just use bulb type thermometers and they never had any problems...
  7. midget_farms

    midget_farms Chillin' With My Peeps

    Apr 15, 2008
    Dunlap Illinois
    I got mine for $.99 off of ebay - The way I see it - just use one & dont stress yourself out too much - set twice as many eggs as you want & you will never be disappointed.
  8. Pascal PicklePants

    Pascal PicklePants Chillin' With My Peeps

    Oct 21, 2010
    Boise, ID
    Quote:I love your logic setting twice the number of eggs [​IMG] ....however..... I can foresee a situation of exponential growth here. Something like "OK i want 24 so i'll set 48.....now that i've set 48, i kinda want all of them to hatch, I better set 96...............etc

    Looks like I better get started on the cabinet incubator.

    By the way I use the Petco dial hygrometer too. calibrated to 71%. not as good as some, but workable.
  9. rebelcowboysnb

    rebelcowboysnb Confederate Money Farm

    You only really need an accurate humidity gauge when you first start or when you are debating the best humidity with other YBCers. After you hatch a few you learn what humidity (on your gauge) works best for you. Lets assume 40% works for you... It doesn't matter if what you think is 40% is actually 40%. What matters is is if you can get back to that 40% on your gauge. Accuracy is nice but consistency is all you need.

    Why is it I always misspell words with real words so spell check fails me......
    Last edited: Feb 3, 2011
  10. snake173

    snake173 Out Of The Brooder

    May 17, 2010
    [​IMG] All of this tecno and special stuff to hatch an egg. That has not changed for longer than I been here. [​IMG] A Bird with a brain the size of a red bean gets all this right and you have almost as much as the T.I. caculator that took us to space. [​IMG] . I would just like to no are we that smart or what. [​IMG]:


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