Kestrel AB showing 0.2% humidity

[jlow]

I have two Kestrels, a 4500NV and an AB. We got in a new basement dehumidifier last week and I was testing its function with the 4500NV – it shows humidity at 45%, just to be sure I turn on the AB and put it to weather mode and check humidity and it says 0.2%... Is it broken?

FWIW, it says "rh uncal" under the reading for the AB- not sure what that means.

I've looked at the manual and it talks about re-calibration using seal containers. I am wondering if I can just calibrate it relative to my other Kestrel. After all, slight inaccuracies in humidity does not affect DOPE that much? The only thing I worry about doing this is what caused the problem in the first place and whether I should send it in?

 

[rduckwor]

I would calibrate it to that reading on the other Kestrel. Why would they not have calibrated it at the factory?

RMD

 

[shoot4fun]

My shooting buddy just got a new (can't remember the model) Kestrel with Link and AB. We spent the last two days at the range trying to get the thing to give us valid data. I don't know if the thing is way smarter than us or just very temperamental but it lied to us more than a Democrat running for POTUS!!!!

 

[JPeelen]

The change in air density due to humidity can also be expressed by the equivalent change in temperature. This is what artillery has been done all the time, calling it virtual temperature.
The difference between 0 percent and 78 percent humidity at moderate conditions is equivalent to a rise of temperature of 1.3 degrees centigrade (2.3 degreesF). Influence of humidity is not large, as you can see. Just calculate a few trajectories and play with humidity.

 

[jlow]

Rduckwor – I am pretty sure they did calibrate it as when I looked at the max, average, and min humidity, two of those values are reasonable. I think it just lost calibration.

JPeelen – as mentioned in my OP, I realize the small effect humidity has on DOPE, I can of course calibrate it to the other machine but my problem is this is like a $600 machine and it would be nice that it would not do this… Especially true since I don’t know what caused it and when it might happen again when I am not looking…. It is still under warranty and so….

Shoot4fun - my AB is very decent in terms of the DOPE it has given me. Having said that, one can get into problem if some of the settings are not input correctly (I know this from experience). If you are having problem, document what you enter for each question the machine ask you and compare your final DOPE to something you trust. You do need to play around with it since some of the entries are not what I call obvious. If you get stuck, come back to the board here or the Hide and ask.

 

[shoot4fun]

Shoot4fun - my AB is very decent in terms of the DOPE it has given me. Having said that, one can get into problem if some of the settings are not input correctly (I know this from experience). If you are having problem, document what you enter for each question the machine ask you and compare your final DOPE to something you trust. You do need to play around with it since some of the entries are not what I call obvious. If you get stuck, come back to the board here or the Hide and ask.

Not slamming the Kestrel. They are great tools but we have yet to learn the tool. If input is incorrect (our case) output will not be correct. Our biggest issue this week was trying to get all the devices to link up with each other.

 

[DocUSMCRetired]

0.2% humidity is a bug in the old units, please send me an email.

Humidity only accounts for .6% of DA, So if humidity is below 50% then less than 1/3rd of a percent in your case. However we can get that unit fixed if you need it.

 

[jlow]

Thanks doc! Unit is on its way to NK