The art of Calibration

[Toasted Coastie]

Originally Posted by tx_tuff

I hate those adjustable ones! I have one and could never get it to adjust! So I just write down what the difference is in what it reads and what it is. Those white digitals ones are great for this because you can just write on back of them with a black marker.

The messed up thing is I thought I had them dead nuts on last time.....

[Mikeyfresh518-cl]

i just bought that accurite
is it spot on all the time or what?
do i need to calibrate it?
u cant even adjust it i mean whats up with that?
can some one help

[Toasted Coastie]

Originally Posted by Mikeyfresh518

i just bought that accurite
is it spot on all the time or what?
do i need to calibrate it?
u cant even adjust it i mean whats up with that?
can some one help

Mike,

I would do the test with a packet to see how far off it is. I bought the two I have pictured in this thread at the same store, at the same time, put the same batteries in it from the same package, and one is -5% while the other is dead on.

I will label one of them with the -/+ RH% with a P-Touch label (it will read like this: + 5%), so I know to add 5% to the reading that I am getting.

I knew that these were not adjustable when I bought it. As you can see from my test so far, even the adjustable ones are not quite adjustable. Which reminds me, I think I will adjust them again tonight, its been two days with the new packet.

[Toasted Coastie]

The two accurite hygrometers are done. I am confident enough in the readings to know that having been in there for a week now, and had a Boveda swap out that

Hygro #4 is -4 to -5% off. I will tag this one as +5% to reading.


Hygro #5 is dead nuts. It has been fluctuating between 75% and 76%. This is awesome because the Boveda pack is actually 75.5%. I'm leaving this one as is.


Hygro's 1, 2 and 3 are going to be adjusted tonight, and will spend more time in the tuppaware. Am I being anal about this? Absolutely.

Hygro 1
66% at 66*

Hygro 2
66% at 65*

Hygro 3
66% at 67*

Not too bad, they are all off only 9%. I'll give them each 9 clicks and see what is up when I get home on Sunday.

[Toasted Coastie]

so, I am convinced now that the small "callibratable" are POS's.



Tonight's readings:

1: 68*f 62%

2: 67*f 67%

3: 70* 61%

So, at this point, I am thinking of buying more of the big ones, because these little ones suck. They are not even close, and I am surprised that I haven't ruined my cigars yet.

I clicked all of the dials all the way to the max to see what will happen.

My advice is to not spend the $24 on these little hygrometers. Go to Wal-Mart, by a cheap digital, throw it in a tuppaware with a cal kit for a few days, note the difference and be done with it. You will save $14 (2 cigars).

[foolwithnohair]

Use the force, Luke, er, use the bag that Boveda gave you. I suspect that there is too much air in your Tupperware without any means to circulate the air. The veriteq link I posted earlier talks about the problems in RH calibration if the air is not actively circulated in the calibration chamber.

I'm guessing that the Wal-marts give you more accurate readings because they have a very small air passage to the sensor so that they can average over a much longer period of time. The cigar ones have the sensor as exposed as possible to catch quick changes in RH, so they are giving you the RH at the location that they are in inside your tupperware, not an average for the whole volume of the Tupperware container (which, as an aside, is why one puts cigar-type digital hydro's right beside/on one's cigars).

All the inexpensive digital hygro's use the same technology - the only difference is the size of the air passages. I wouldn't be surprised if your Wal-mart one has a hole the diameter of a paper clip for air to reach the sensor, and the round ones have the sensor almost completely exposed.

Given your determination to get to the bottom of this, I'd try putting your Walmart and one circular one in the Boveda zip-lock (or any zip-lock) with the calibration pack and seeing what happens. You may be pleasantly surprised.

[Toasted Coastie]

Originally Posted by baldheadracing

Use the force, Luke, er, use the bag that Boveda gave you. I suspect that there is too much air in your Tupperware without any means to circulate the air. The veriteq link I posted earlier talks about the problems in RH calibration if the air is not actively circulated in the calibration chamber.

I'm guessing that the Wal-marts give you more accurate readings because they have a very small air passage to the sensor so that they can average over a much longer period of time. The cigar ones have the sensor as exposed as possible to catch quick changes in RH, so they are giving you the RH at the location that they are in inside your tupperware, not an average for the whole volume of the Tupperware container (which, as an aside, is why one puts cigar-type digital hydro's right beside/on one's cigars).

All the inexpensive digital hygro's use the same technology - the only difference is the size of the air passages. I wouldn't be surprised if your Wal-mart one has a hole the diameter of a paper clip for air to reach the sensor, and the round ones have the sensor almost completely exposed.

Given your determination to get to the bottom of this, I'd try putting your Walmart and one circular one in the Boveda zip-lock (or any zip-lock) with the calibration pack and seeing what happens. You may be pleasantly surprised.

OK, I'm game.

I actually put all of the small hygro's in a smaller Tupperware after I removed the Wal-Mart ones. However, i will take one of the calibratable ones (hygro 1) and one of the non-calibratable ones (hygro 4) and put it in the bag the pack came with. I'll report on it on Tuesday, giving it more than one day.

As an aside, the Wal-Mart hygro's vent area above the sensor is a larger area than the small ones. i will post pics later (on a different machine right now.)

[foolwithnohair]

It is the size of the hole below the sensor that counts.

(Geez that sounds NSFW )

[Toasted Coastie]

Originally Posted by baldheadracing

It is the size of the hole below the sensor that counts.

(Geez that sounds NSFW )

That's what I meant I guess...

[Toasted Coastie]

The small one still has not budged, but the large one has remained between 69%-70%

These small ones are crap.

Also, I have decided to add this one to the mix. $7.69 @ Home Depot:



It's reading high because I breathed in the vent to test the sensor. I have put all the small ones, the large one, the new one and my Weather Chanel remote sensor one back in the tuppaware.

[Huskysibe]

Dont forget to calibrate your hygrometer in the same place where your humi is. This makes a difference as sunlight, AC Vents etc will affect the reading. What I do is put the Boveda pack right on top of the humi so it is in the same position that it will remain in the humidor. Maybe its anal but its what I like to do.

Billy

[Toasted Coastie]

So I have found that the small "calibrate-able ones are no longer what I want to use. So if you think that buying one from a cigar site or shop is going to be better than anything else, well in my opinion you are throwing money away.

Right now I am using the following:

2 of these. One I have to add 5%, the other was dead on.


1 of these. I have to add 2% to it. This one actually has a remote sensor working off a 915mhz wireless band. Like $20 @ Home Depot.


1 of these. I have to subtract 3%


The calibrate-able ones are not calibrating, even with fresh batteries. they are staying over 9-11% under 75%

[mhlatke]

My head is spinning after this thread. Very informative but also very frustrating. It's a shame they can't just make a reliable hygrometer that would save us all a lot of grief. Now I feel like I have to go re-test all my units - thanx!

[Toasted Coastie]

Originally Posted by mhlatke

My head is spinning after this thread. Very informative but also very frustrating. It's a shame they can't just make a reliable hygrometer that would save us all a lot of grief. Now I feel like I have to go re-test all my units - thanx!

No kidding. Dude, it's a suck sandwich all the way around.

[SMOKE20]

What brand are those from walmart.

I hate going to wally world to shop