Hygro calibration

[NullSmurf]

I'm using a 2 quart Tupperware brand container with about 1/2 ounce of salt, neatly damp - barely visible in the upper right.

Inside are my Radio Shack temp/hygro with external wired sensor, removed. It shows "LLL" where that temp would read. The smaller analog is a Thompson special. The larger came with my newest 150 stick humi. This shot is taken at 8 hours.

 

[NullSmurf]

at 16 hours, the larger analog has inched up to 70%, the smaller solid on 75%. I've calibrated and adjusted the smaller previously.

The Radio Shack digital is stuck at 61. I'm not too impressed. Following my last attempt, I cracked it open and found one potentiometer. I don't have a schematic, so I have no idea what its for. I tweaked it anyhow to see what affect it might have. There was no obvious change. I did drill a hole in the case so I could access it, just in case. I'll shoot one more pic at 24 hours, then I'll adjust the large analog.

 

[NullSmurf]

I finished the calibration of the two analogs and tossed the digital. Quality digitals aren't expensive. This has been an education.

 

[Sunward]

ya, those digi are not too accurate.. radio crap of mine is off, +5%, analogue are fine

 

[symyn]

It's funny because every thread I read when I started with my humidor said don't go by analogs buy exclusively digital.

 

[Gunpowder]

1-I would have checked the batteries first.
2-salt test is a must
3-I am looking at my radio Shack remote right now. 67%
4. The two models I use are both Radio shack and work very well.
5. Most analog dials are crap IMO

 

[Shibumi]

The key to the test is an "airtight" seal to get the right reading. The tupperware and ziplocks are not airtight.

I did a test today. I set up the salt test in a pelican (otterbox type) case before work. I came home 9 hours later and my digital read 70%. I turned on the light, went into the kitchen to cook some Omaha Steaks and a few minutes later it was reading 68%. So I put the case in a dark place and hung out. A few minutes later it was back to 70%. I didn't realize that light had something to do with RH.

Either way, It should be airtight and probably in the dark.

 

[BlindedByScience]

The key to the test is an "airtight" seal to get the right reading. The tupperware and ziplocks are not airtight.

I did a test today. I set up the salt test in a pelican (otterbox type) case before work. I came home 9 hours later and my digital read 70%. I turned on the light, went into the kitchen to cook some Omaha Steaks and a few minutes later it was reading 68%. So I put the case in a dark place and hung out. A few minutes later it was back to 70%. I didn't realize that light had something to do with RH.

Either way, It should be airtight and probably in the dark.

[snapback]291977[/snapback]​

QFT. You should try your test again, with the tupperware in a ziplock bag. I about went crazy trying to get the same results twice with a salt test until I started "double bagging" everthing. Then and only then did the results have any repeatability to them at all.

The little digitals that Rod sells here as well as a couple of other brands I can think of are usually very consistant, and very accurate. Battery replacement once a year is my normal maintenance for these.

FWIW - B.B.S.

 

[symyn]

The key to the test is an "airtight" seal to get the right reading. The tupperware and ziplocks are not airtight.

I did a test today. I set up the salt test in a pelican (otterbox type) case before work. I came home 9 hours later and my digital read 70%. I turned on the light, went into the kitchen to cook some Omaha Steaks and a few minutes later it was reading 68%. So I put the case in a dark place and hung out. A few minutes later it was back to 70%. I didn't realize that light had something to do with RH.

Either way, It should be airtight and probably in the dark.

[snapback]291977[/snapback]​

Correct me if I am wrong but shouldn't the salt test equal out to 75% RH?

 

[Shibumi]

The key to the test is an "airtight" seal to get the right reading.  The tupperware and ziplocks are not airtight.

I did a test today.  I set up the salt test in a pelican (otterbox type) case before work.  I came home 9 hours later and my digital read 70%.  I turned on the light, went into the kitchen to cook some Omaha Steaks and a few minutes later it was reading 68%.  So I put the case in a dark place and hung out. A few minutes later it was back to 70%.  I didn't realize that light had something to do with RH. 

Either way, It should be airtight and probably in the dark.

[snapback]291977[/snapback]​

Correct me if I am wrong but shouldn't the salt test equal out to 75% RH?

[snapback]291998[/snapback]​

Yeah, I should mention it's always been 5% off. I just keep it at 60% all the time.