I am getting leary of the accuracy of my mechanical hygrometers and want to get a good digital to use for verification. Any suggestions and do they need to be calibrated?

I bought one from cigarbid and it works great.

Digitals work real well and don't need to be calibrated. You can pick one up right here at CB for less than you would in a local shop.

I wouldn't pay more than 25.00 for a small unit.

A couple of things though, if you are OCD wih regards to humidity and temperature on your cigars (ahem, like me), the digitals can be a blessing and a burden.

Why? The darn things are quite accurate and everytime you open the lid, you may feel compelled to add more solution or water to your humi's!~

I would definately recommend anyone who bid's here to have one. Seeing how much money is spent here, you can't afford to let your sticks go bad.

Digital hygrometers react more quickly to fluctuations of the humidity and measure often with higher accuracy. Please note that digital hygrometers also need some time to adapt to changes in humidity and will not show changes instantaneously.

Even with digital hygrometers for professional laboratory use at prices of more than 80 US$, manufacturer guarantee only an accuracy of + / - 5%.

Digital hygrometers are more accurate and require no calibrating.

I have a few digital hygrometers and I find it wise to do the salt calibration test. They may read 65% when it's really 70%. Once you know how far off they are it's a no brainer. I have 1 cheapy that reads exactly 11% low. I took it for granted that it was correct when I first got it and couldn't figure out why my cigars were so wet.

Barry

yeaup, I have several. most work well, one reads consistently 7% low.

Any brand in perticular?

Slimboli

these 2 sentences are incongruous.

Even with digital hygrometers for professional laboratory use at prices of more than 80 US$, manufacturer guarantee only an accuracy of + / - 5%.

Digital hygrometers are more accurate and require no calibrating.

Rick --- why are those two statements inappropriate or out of place?

Both are true ... as even though the most expensive digital hygrometers can only gurarantee their accuracy to +/- 5% ... they are still more accruate and dependable than analog, and require no calibration.

can you even calibrate digitals?

I don't think it's advisable, although Rickamaven posted something about it awhile back ... but was very enigmatic in how it was accomplished.

Slim is wondering how Rick accomplishes giving himself an enigma. I would wonder, too, but I am afraid to think about it.

LMAO. X

eleltea

fleet, but keeping it in the icebox before you use it is not a good idea

Slimboli

not inappropriate or out of place. i just don't understand why a tolerance of 10% is considered

accurate. you are correct the digital should be more accurate but having calibrated all my digital

and analog hygrometers, i can put them all in the same box and they will all read within 1% of

each other.

i guess i didn't explain the digital calibration technique properly.

the calibration for both digital and analog is exactly the same, damp salt in a sealed bag and the

humidity should read 75% on the device being calibrated.

with an analog, you turn the adjustment screw on the back, with a digital you have to get into the

inner working and find what i called a potentiometer, used in the loosest term.

a potentiometer refers to a sensing device that measures and can adjust electrical current, like

volume from a radio. (do they still call them radios?)

in a water heater it's not called a potentiometer but a thermocouple, and it measure and adjusts

for temperatures, set the temperature of the water you want, and the thermocouple maintains it..

i don't know what it is called in a digital hygrometer, but it works on a similar principle, except it

only measures the humidity but does not adjust it.

the reading on a digital hygrometer can be adjusted using the calibration screw on the "pot"

located inside the case using a jewlers screw. some digital hygrometers will come with calibration

instructions with a picture showing where the pot is located.

http://www.cigargroup.com/faq/ 

6.2 Radio Shack #63-855 Calibration

Ok! Feeling "scientific after testing the calibration of your hygrometer? Well, the next step for the

ambitious among us is to actually callibrate our hygrometers. Many cybersmokers use the Radio

Shack 63-855 Hygrometer, (also known as the "Airguide" Hygrometer). The following procedure

was written specifically for that instrument. Please read these instructions very carefully before

proceeding - If you don't feel comfortable tinkering with sensitive circuitry, DON'T DO IT!

Now that you know how far your instrument is out, you might want to adjust it. CAUTION! Mess-up

here, and you could damage your hygrometer! There is no simple calibration knob to turn. To

adjust this instrument, you'll be re-adjusting the bias current of the sensor, then comparing it to

your calibration reference - the salt in the baggie.

Remove the battery door, the batteries, and finally the back of the unit. along the top edge of the

PC board inside, you'll see two round, flattish metal disks (micro-potentiometers). don't touch the

left one, you'll be working only with the one on the right. First, look at it closely. You'll see a tiny

indent for a tiny screwdriver blade across the middle. Sketch its exact position carefully - this

procedure might take several days, and you will forget the original orientation if you don't write it

down!

You'll be turning this right potentiometer (pot) a tiny amount to change the humidity reading (1/8

turn might change your reading by 3 or 4%). DO NOT turn it more that 1/4 turn! Use a very small

screwdriver (like a jeweler's screwdriver), and don't change it by much! If you were reading above

75% in the calibration test, turn this pot clockwise, again only a tiny amount... If your reading was

low, turn it slightly counter-clockwise...

You can leave the back off to save some effort, and put the batteries back in now. Be sure the

"min" and "max" functions are turned off, and place the hygrometer back in your baggie with the

salt. Again, let it stabilize for 6 hours, and DON'T LET IT TOUCH THE WET SALT! Check your

reading, and re-adjust if necessary. Be patient, you may have to try a few times to get it right. If

you feel you're getting nowhere, set the pot back to exactly where it was when you started.

When you're satisfied with your setting (set it to +- 1% of 75%) remove the batteries, re-assemble

the unit, and give it one final check. Once you're done, light up one of your best cigars - you'll

deserve it!

Radio Shack #63-1013 Calibration

The Radio Shack model 63-1013 hygrometer can be calibrated similarly. The potentiometer (pot.)

can be found on the upper left hand side of the circuit board once the back is removed. The pot. is

small -- about half the diameter of a pencil eraser. The pot. has a small slot in it to allow for

adjustments. Clockwise turns increase the humidy percent reading and counter clockwise turns

decrease the reading.

6.3 Older Radio Shack units

contributed by Steven Banks

I would like to add some new information. I have one of the older Radio Shack hygrometers #63-

844, but do you think that stopped me? You give me an opportunity to take something I know

nothing about apart, I'm there! Plus, my Dad was a quality assurance engineer and he wouldn't

have put up with that much of a error factor.

Well the salt portion of this whole procedure is sweet indeed - so simple, I felt like I was watching

"Mr. Wizard" again. After doing this I found that my hygrometer was a whopping +8% off. Now...

I'm not great with math, so I decided to correct the problem instead of just knowing how much it's

off by. The problem was, which "pot" screws to adjust, since the instructions were for a #63-855.

Well for those of you that have the same model as I do, there are two circuit boards in it, the top

one is for the temperature and the bottom is for the humidity. The "pot" screw CLOSEST to the

battery compartment is the one you need to adjust. And yes, as was mentioned in the first posting,

it does take some fiddling!!! There were times I'd adjust the screw, and see no change. But I

finally got that puppy within + -1%. Note that this hygrometer's reading will INCREASE as you turn

the control CLOCKWISE - exactly the opposite of the 63-855 model...

Let it be known that I tinkered where no person in their right mind should, and this is no guarantee

that it'll work for you (especially knowing Radio Shack stuff - yours could be laid out differently?)

But if you're bold, go where no man has gone before and make it right!

That does sound complicated. How about spitting in the back of it and giving it a good a little smack. Thanks to all for the responses - BUD.

like we used to do with a tube radio and i still do with one of my tv sets.