Accuracy of hygrometer in dry box/cabi vs usefulness


pstiang

New Member
Jan 19, 2010
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I have a digital cabi, with digital RH setting. What i found out was:

I set my cabi to RH 45%. When the cabi shows that it reached 45%, my another xtra analog hygrometer which is inside show RH 55%
I changed the analog hygrometer position to another tray in my cabi, and it will stay at RH 65& for the rest of the time.

This experiment shows that the RH in cabi is not fixed throughout? And it clearly shows digital and analog hygrometers are not 100% accurate.

The problem is this, most of us know that a dry box/cabi is best to keep at 40-50% for our cameras n lenses, but, how many of us know that the hygrometer of ur box/cabi is accurate? For those whose box/cabi is actually higher than RH50%, and their hygrometer is showing 45%, think that their camera and lenses are safe from fungus?

At this point of time, I am sure many of us bought what is call "something to protect our equipment", but actually its not protecting it.

Solution? Get a accurate hygrometer. Cost some more $$. But, will anyone do it?
Anyone has a cheaper method to check if the hygrometer on the box/cabi is accurate?
 

i have a 38L AIPO dry cabinet (2 tier) so i bought 2 digital hygrometer for each tier in addition to the original meter on the dry cabinet. i set 40% RH for my cabinet and my 2 external digital hygro indicates RH 45-46% so overall i'm pretty pleased with the performance
 

You have a possible choice. One is to lower till 35% using the build in meter, so if the backup hydrometer is the one giving the correct reading, then you will still have 50%, still not too bad as compared to 65%-75%

So the choice is yours, leave with potential fungus or leave with unfounded theories of dried oil, cracking plastic/rubber and PVC circit board.

...This experiment shows that the RH in cabi is not fixed throughout? And it clearly shows digital and analog hygrometers are not 100% accurate.

The problem is this, most of us know that a dry box/cabi is best to keep at 40-50% for our cameras n lenses, but, how many of us know that the hygrometer of ur box/cabi is accurate? For those whose box/cabi is actually higher than RH50%, and their hygrometer is showing 45%, think that their camera and lenses are safe from fungus?

At this point of time, I am sure many of us bought what is call "something to protect our equipment", but actually its not protecting it.

Solution? Get a accurate hygrometer. Cost some more $$. But, will anyone do it?
Anyone has a cheaper method to check if the hygrometer on the box/cabi is accurate?
 

just throw and put in millions of silica gel will do ;)
 

I think best is have hygrometer calibrated. do "salt test" with an extra analog/digital hygrometer and compare with the one in ur box/cabi. This way, you can confirm that your dry cabi/box is protecting your equipment.
 

Got a digital Hydrometer recently, while my analog meter reading is at 45%, the digital reading will be at 31-34% :confused:

Did a "salt test" last night, both meters reading are quite close to 75%.

Now I don't know which meter to trust. :confused:

Any body encounter this before?
 

Got a digital Hydrometer recently, while my analog meter reading is at 45%, the digital reading will be at 31-34% :confused:

Did a "salt test" last night, both meters reading are quite close to 75%.

Now I don't know which meter to trust. :confused:

Any body encounter this before?


For how long did you do your 'salt test'? It has to be done for 24 - 36 hours.
 

Actually i just trust whatever reading the meter gives me.

The only time i got abit more uptight was when the meter went blank
( changed battery and hey presto .. )

but interesting read nevertheless.

ryan
 


If that is the case, then one of your hygrometers is probably not accurate at that RH range.
The Caliber III digital hygrometer, for example, claims to have an accuracy of +/- 1% at RH range of 40%-80% and +/- 3% outside that RH range. :)
 

i might be wrong, but my cabinet was advertised as +- 10% RH. I prefer leaving it hovering around 30 to 35% to offset the error margin
 

Hi peeps...did a search but can't find an answer (perhaps my search was wrong?)
anyway..my question is... on average..how long it takes the dry cabinet to reach 45% RH upon open up?

jus bought my digi-cabi 30L.. i set it up at 7.30pm..but till now..it is still hoverng at 53% RH..i set it to maximum also...
btw...the current time is 9.28pm..which mean..i haf turned on for about 2 hrs plus..

kindly guide..

thanks!
 

I think best is have hygrometer calibrated. do "salt test" with an extra analog/digital hygrometer and compare with the one in ur box/cabi. This way, you can confirm that your dry cabi/box is protecting your equipment.

Hi, just thinking how do we know which hygrometer is giving the correct reading? :dunno: