Why you should always test you hygrometers before you start incubating

[4-H chicken mom]

I just bought a new Acurite with a probe and something told me to check the calibration on it using the salt water method before I put it in my hatcher. Thank the lord I did. It was in the bag overnight (12hrs) and it never got above 65%. If I would have used it, my readings would be off by 10. I would have surely drowned my duck eggs. I would have thought the hatcher was at 75% when it really would have been 85%.

I am taking this one back. The first Acurite I purchased a few years ago is only off by 4. I figured this one would have been close also.
This just goes to show, you should always test your hygrometer before you begin your hatch. This might be the cause for some that can't understand why the eggs are dying when you think you are keeping the right numbers.

 

[beerman]

I've had the same problem I will never use one without testing it again!!!

 

[Chickenfarmer 1-2-b]

I bought a few Accurite therm/hygro in the past, seems like all of them report lower RH than they supposed to.

 

[tammyd57]

We have an Oregon Scientific Treviso Weather Station that my husband won in a drawing a couple years ago. We never used it but it looks like we have a real good use for it now! I have it in a plastic bag w/salt slurry to see what it will say in the morning.
I thought it was kind of a cheap win until I just looked them up to see how much they sell for. Wow! I sure hope price reflects accuracy, that's something I wouldn't want to have to shell out money for!

 

[lexgold]

Can you explain to me how you test the hygrometer's in a bag please? Are you referring to the digital Springfield types or is this something with a probe that you stick in the bag?! Fogive my ignorance...I'd like to test mine

 

[tammyd57]

Mine is digital. You put it in a large zip bag with a cup containing 1/2 cup of salt and 1/4 cup of water (making sure they are not touching) for 12 hours. Then you see what it says the humidity is. It SHOULD say 75%. If it is off one way or the other you know how much to adjust for the reading in the incubator. For instance, if it says 70% in the bag, remember to add 5% to the reading when it's in the incubator.

 

[pascopol]

I prefere good quality analog hygrometer which can be calibrated, and I calibrate mine using salt method before every hatch.

I found that digital hygrometers even expensive ones deteriorate over time and show wrong readings as the time go by. Most of them can not be calibrated.

Also be careful with digital thermometers, same principles apply. Another problem with digital is when battery becomes weak, it may affect the accuracy of the reading. Happened to me once or twice.

I have 2 quality analog therms with .5 F accuracy scale, one alcohol and one mercury.

I always run analog therm with my digital to confirm readings, using digital therm for quick glance any time and once a day comparing the reading with analog therm which is more difficult to read than digital.

This way I never had botched hatches caused by humidity or temperature problems.

If you have to go with cheap analog therm, I found the most reliable and accurate are aquarium floating therms but not the type you glue to aquarium side (Walmart, around 2 bucks or less) but need to be verified using trusted therm to be safe.

If you buy one look up a bunch off the shelf and pick one showing same temp as most others, chances are it will be accurately calibrated, meaning if there is 5 of them and 3 read 70F one 69F and one 71 you pick one of those showing 70F. Also make sure it goes up to 100 F.

You still have to compare it with tested one, but I would say you have a 90% chance of picking a good one.

 

[ArizonaDesertChicks]

I have a new acurite & a new springfield and assumed they were correct because they were always withing 1-2 degrees of each other while in my incubator. I tried the salt water calibration test on the springfield a couple days ago and found it off by 10% - it never got above 65% either. How accurate is the salt water test - is it fool-proof? If so, then both of my hygrometers are at least 10% off and I've been incubating for the last 2 1/2 weeks at 10% higher humidity than I though. Lockdown is tomorrow and I really need to know whether I should trust my two hygrometers or the salt water test.

 

[The Point]

CRAP!!!! I just bought the same one a few days ago. I am already in lockdown and day 21 starts the evening of the 24. I have been freaking out all day because I couldn't get my humidity above 62. I didn't know about calibrating them till now. I have a lot of condensation on the window. I have a manual one I could calibrate over night and pop it in the morning. Which is more harmful to my babies, opening the bator for a second to stick the manual in or having my humidity possibly be super high?

 

[momma-hen]

Quote:
I hate to sound stupid (but I'm good at it!!) but make sure what isn't touching? Are the salt and water in seperate cups?