Hygrometer questions

blondie · 11/12/2014 07:41 PM

So I calibrated these two Hygrometers about two weeks ago using the salt test. Both units in the same plastic bag, same ambient temp, same time. They were in different humidors. Fast forward and I picked up the new whynter cigar cooler unit, so I was seasoning, etc, moving cigars and what not. I moved the two hygrometers to the new cooler, so I could make sure where the humidity was getting to, and got two different results. See photo:

I was waiting on a new hygro, the western caliber IV, got here yesterday, let it sit in a Boveda calibration kit for 26 hours or so, calibrated it (needed +1), and it is in the new humidor reading 66% with 65% heartfelt beads as the humidity medium:

Anyone have any thoughts on Boveda calibration kit vs the salt test? I am re-calibrating the Xikars now, and will put them back in the humidor after that to see if there are closer readings. Would like to get as close as possible.

ntanner · 11/12/2014 07:49 PM

They both work well, you have to make sure the salt is done correct. A tupperware dish works better then a baggie when performing a salt test I think, but that is just me. Also, I dont know how much time they had in the humi before the photo but they may adjust or equalize at different rates.

blondie · 11/12/2014 07:53 PM

Quotentanner - 11/12/2014 9:49 PM They both work well, you have to make sure the salt is done correct. A tupperware dish works better then a baggie when performing a salt test I think, but that is just me. Also, I dont know how much time they had in the humi before the photo but they may adjust or equalize at different rates.

They were in there for a solid 24 hours before I took that picture. The Western Caliber IV has only been in there about two hours, and it is now reading 67%. Will check it again in the morning. I also have some mesh bags coming from heartfelt, and maybe adding another 1/2 pound of beads will get it to stay closer to the 65%.

DonM · 11/13/2014 05:02 AM

When was the last time you changed the batteries in the Xikars? If it has been quite awhile you may want to try that.

Just a suggestion, maybe try calibrating all 3 again at the same time? Remember, you are working with a device that has Xikar +- 2 % RH and the Caliber +- 1 % RH tolerance. You may not be able to get them to read exactly the same but I would think you can get them within 1 %?

The new Xikars you can't calibrate, the new Caliber you can

I recall not long ago that I saw something from Xikar? about going to non calibration because we are idiots and don't know how to do a salt test properly

blondie · 11/13/2014 07:40 AM

QuoteDonM - 11/13/2014 7:02 AM When was the last time you changed the batteries in the Xikars? If it has been quite awhile you may want to try that. Just a suggestion, maybe try calibrating all 3 again at the same time? Remember, you are working with a device that has Xikar +- 2 % RH and the Caliber +- 1 % RH tolerance. You may not be able to get them to read exactly the same but I would think you can get them within 1 %? The new Xikars you can't calibrate, the new Caliber you can I recall not long ago that I saw something from Xikar? about going to non calibration because we are idiots and don't know how to do a salt test properly

The batteries had died and I changed them out, and that is why I re-calibrated. As an update, the one that was reading 3 points higher, is sitting at 79% with the Boveda, while the other is at 75%. Been in the bag for about 15 hours. I think we obsess over accuracy, and the reality is there is as much art to cigar storage as there is science. Will report back after calibrating and some time back in the humidor. The good news is that the new Whynter unit appears to be right at 66%, stable. Now I need to spend some time going through it and deciding which cigars to leave in there for long term aging, and which ones to put into the "on deck" humidor. Well, Humidors to be precise.

DonM · 11/13/2014 08:08 AM

I agree we can be OCD about RH. Anymore I use my Caliber III as a guide, when the RH drops below 62% I give the beads a little spray, works for me

Jackal · 11/13/2014 11:15 AM

This is why those of us who deal in metrology professionally do not do single point calibrations. You can get two devices that read the same at one point and then vary considerably at a second one.

The best method for standardizing an instrument is to do a three point test (bracketing high and low values and hitting the middle point in your typical measurement area) and checking for linearity. Unfortunately, it is difficult to get three standardized points when dealing with relative humidities. Still, if you can check against a couple of fixed points (Bovedas possibly) you can get a rough idea of your Repeatability and Reproducibility for each hygrometer.

Sadly, it seems that most commercially available hygrometers are nowhere near as good as we like to believe that they are or would like them to be (even the digital ones).

If you really want to be either OCD or bored out of your mind, do an internet search on the topic of gauge R&R.

Longhorn · 11/13/2014 12:16 PM

QuoteJackal - 11/13/2014 2:15 PM

This is why those of us who deal in metrology professionally do not do single point calibrations. You can get two devices that read the same at one point and then vary considerably at a second one.

The best method for standardizing an instrument is to do a three point test (bracketing high and low values and hitting the middle point in your typical measurement area) and checking for linearity. Unfortunately, it is difficult to get three standardized points when dealing with relative humidities. Still, if you can check against a couple of fixed points (Bovedas possibly) you can get a rough idea of your Repeatability and Reproducibility for each hygrometer.

Sadly, it seems that most commercially available hygrometers are nowhere near as good as we like to believe that they are or would like them to be (even the digital ones).

If you really want to be either OCD or bored out of your mind, do an internet search on the topic of gauge R&R.

Damn it, Jackal. You beat me to the post every time. This is exactly what I was going to say.

Brlesq · 11/13/2014 01:58 PM

QuoteLonghorn - 11/13/2014 3:16 PM

QuoteJackal - 11/13/2014 2:15 PM

This is why those of us who deal in metrology professionally do not do single point calibrations. You can get two devices that read the same at one point and then vary considerably at a second one.

The best method for standardizing an instrument is to do a three point test (bracketing high and low values and hitting the middle point in your typical measurement area) and checking for linearity. Unfortunately, it is difficult to get three standardized points when dealing with relative humidities. Still, if you can check against a couple of fixed points (Bovedas possibly) you can get a rough idea of your Repeatability and Reproducibility for each hygrometer.

Sadly, it seems that most commercially available hygrometers are nowhere near as good as we like to believe that they are or would like them to be (even the digital ones).

If you really want to be either OCD or bored out of your mind, do an internet search on the topic of gauge R&R.

Damn it, Jackal. You beat me to the post every time. This is exactly what I was going to say.

Maybe so, but if I ever go out on a "3 hour tour", I'm taking Jason, not you!!

ntanner · 11/13/2014 05:11 PM

QuoteBrlesq - 11/13/2014 2:58 PM

QuoteLonghorn - 11/13/2014 3:16 PM

QuoteJackal - 11/13/2014 2:15 PM

Damn it, Jackal. You beat me to the post every time. This is exactly what I was going to say.

Maybe so, but if I ever go out on a "3 hour tour", I'm taking Jason, not you!!

blondie · 11/14/2014 04:14 AM

Well, after sitting in the calibration bag for 36 hours, the one reading closest was at 75%, and the one reading high was at 79%. Pressed the calibrate button, and it did not calibrate to 75%. So I'm thinking that one was bad.