Calibrating a Hygrometer

[Knittycat]

I have my hygrometer sitting in a plastic zip-loc bag with a cup containing 1/2c salt and 1/4c water.
What temperature should I let this sit at? Room temp? That's hovering in the upper 60s at the moment. Should I put it in the window to catch the sun? Or should I quit worrying LOL

 

[fried green eggs]

Room temperture is fine. Forget about it for now. It should be 75% after 8 - 12 hrs. If not you need to add or subtract the difference.

 

[bargain]

I have my hygrometer sitting in a plastic zip-loc bag with a cup containing 1/2c salt and 1/4c water.
What temperature should I let this sit at? Room temp? That's hovering in the upper 60s at the moment. Should I put it in the window to catch the sun? Or should I quit worrying LOL

Your room temperature will not affect the test unless it is like 34 and causes the water to freeze: Here's my best doc on calibration and how to do it. Hope it helps:
Hygrometer Calibration: Mix 1/2 cup salt vigorously in 1/4 cup water. Pour mixture into a dry cup carefully as to prevent any of the solution from getting on the outside of the cup. Place the cup of solution in a large ziploc bag on a flat surface. Place new batteries in your hygrometer, turn it on and place it in the bag beside the cup of solution. Zip the bag shut carefully and wait 12 hours. Read the results of the humidity on the hydrometer before opening the bag. The hygrometer should read 75%. If it does not, read the hygrometer by adding or subtracting the result from 75% once it is in your incubator.
Example: If your meter reads 72%, you will know it is off by 3%. Once in the incubator, you will add 3% to the reading. The opposite applies if the hygrometer reads more than 75%.

 

[Knittycat]

I only ask because I did have it in the sun and the humidity was at 76%, and then I moved it out of the sun and it dropped to 73%. I left it about 8 hours for the first part and another 1 hour for the second.

 

[pinky67]

Thanks for the info! I need to do this!

 

[bargain]

I only ask because I did have it in the sun and the humidity was at 76%, and then I moved it out of the sun and it dropped to 73%. I left it about 8 hours for the first part and another 1 hour for the second.

Okay I'm understanding you now. Obviously the temp was higher in the sun. And that would affect the consistency of your testing. When I test, I try to put in an environment where the temp is fairly stable. Just like a car will heat up 10 to 20 degrees more and in the summer even more degrees, that window is "superheating" your environment.... In a incubator setting for example, when you add more water, up the humidity, the temperature will decrease, Less humidity, higher humidity for the inc.

Hope this helps you. and pinky 67, glad this info can help you.

 

[Knittycat]

So the humidity reading will be temperature dependent then? :/ eh. I don't need it to be precise I guess. All I really need is a ball-park figure to know if I've got it too high or too low.