Humidity Test Discrepencies?

[Lizzy733]

Hey guys,

I've just been calibrating my temp/humidity sensors ahead of my impending egg delivery, but had some discrepancies in the readings.

I set it up yesterday evening and almost forgot to check it- at around 6-7 hours, it was reading 80%. I left it set up over night and rechecked this morning and it was 76% - which one should I go by?

We are in a humid environment and ambient humidity in the room was likely around 60-70 before the bag was sealed. Had it not had time to completely settle the evening before?

I can't imagine it 'lost' water, as the bag was sealed. Anybody with a bit more experience at hydrometer calibrations that can weigh in?

I will be weighing my eggs and will likely be going dry to start, considering our climate, but would like to figure out the discrepency and find out which reading is the accurate one.

 

[JDGreene]

Exactly what was the process did you do to calibrate your hygrometer?

 

[Lizzy733]

Exactly what was the process did you do to calibrate your hygrometer?

Bottle cap full of salt, dampened, then put in sealed ziplock bag with hydrometer and left alone. 6-7 hour reading was 80%, but reading next day (13-14hr) was 76%.

The bag is larger, but so is the hydrometer. Tried to reduce the amount of air in there when sealing. My understanding is that this should have leveled the humidity to 75% after 6 hours, but the two different readings have me confused. I would have expected it not to change overnight as it did with the bag being sealed.

Below is the bag and salt minus the hydrometer.

 

[aart]

Tried to reduce the amount of air in there when sealing.

That might have done it?
Bag shifted and spread out the moisture.
I try to have bag full of air.

 

[Lizzy733]

That might have done it?
Bag shifted and spread out the moisture.
I try to have bag full of air.

Maybe, I didn't touch it overnight though. Will have to give it another go. My bags are big, but we're in lockdown, so can't justify popping down to get alterative sizes at the moment.

I still need to get batteries for the other probe I want to use. If the hydrometer ends up only being 1% off, I'll be pretty impressed. I'm pretty sure it's a brewer's/industrial thermometer, excess from my reptile setup and was only .8 degrees over on the freezing water test, so more accurate than I expected. It has an in/out reading and the in looks to be maybe another .2 degrees higher, so overall impressed by it's accuracy so far.

 

[aart]

Maybe, I didn't touch it overnight though. Will have to give it another go. My bags are big, but we're in lockdown, so can't justify popping down to get alterative sizes at the moment.

I still need to get batteries for the other probe I want to use. If the hydrometer ends up only being 1% off, I'll be pretty impressed. I'm pretty sure it's a brewer's/industrial thermometer, excess from my reptile setup and was only .8 degrees over on the freezing water test, so more accurate than I expected. It has an in/out reading and the in looks to be maybe another .2 degrees higher, so overall impressed by it's accuracy so far.

Temp is different.....much more complex scenario.
Need to know range of therm before testing with ice/boil.

 

[JDGreene]

Bottle cap full of salt, dampened, then put in sealed ziplock bag with hydrometer and left alone. 6-7 hour reading was 80%, but reading next day (13-14hr) was 76%.

I've never seen my hygrometers go up and then settle to a lower percentage. I'd go with the 76% reading, so you are 1% too high. I use gallon and quart ziploc bags, puffed up, and they seem to come up with the same reading after 12 hours. I use 1 tablespoon sodium chloride and 1 teaspoon of water.

What hygrometer are you using?

I just use the Accurite hygrometer/thermometer that you can get at lowes or walmart. Models have changed through the years. Every one I've had the reading is off, none are the same. The thermometer part of those are slow read and not worth using but the hygrometer part works good if you calibrate it.

 

[Lizzy733]

I've never seen my hygrometers go up and then settle to a lower percentage. I'd go with the 76% reading, so you are 1% too high. I use gallon and quart ziploc bags, puffed up, and they seem to come up with the same reading after 12 hours. I use 1 tablespoon sodium chloride and 1 teaspoon of water.

What hygrometer are you using?

I just use the Accurite hygrometer/thermometer that you can get at lowes or walmart. Models have changed through the years. Every one I've had the reading is off, none are the same. The thermometer part of those are slow read and not worth using but the hygrometer part works good if you calibrate it.

Not in the US, so a bit more limited on availability. Have had these for ages, but have never calibrated cause they're excess from my reptile Viv and I've never had a need for them to be so accurate as they've been more for hot-spot cold-spot testing. The one in question is labeled as a KTJ TA318 and is a big box of a thing, but is faring well so far.
I have a new thermostat probe in the Viv, which I tested at .5 degrees over 0c with the same ice melt water, both leveled out within a minute of probing so they're pretty quick to get to temp. My old thermostat was a whopping 5 degrees off once it settled, and the laser was, I think 1.6, but would only be able to read from the surface, so not sure since that one can't be submerged.

Pretty sure that temp calibration was accurate. Really, that's the only important one, as the incubator I have coming is cheap and I will 'grain of salt' whatever it says, so want a trusted reading to set it by.

I'll be weighing every 6 days anyway, so the humidity is less important, but interesting to know how accurate my reader is. Humidity here is quite high in general, currently reading 61% indoors and it's a warm sunny day, so going to start out dry and see how much the brooder drops to once it's warmed up, may end up a dry hatch.