You can heat them one at a time.
Sent via the Samsung Galaxy S™ III, an AT&T 4G LTE smartphone
-------- Original message --------
From: Mick Sulley <m...@sulley.info>
Date:04/07/2014 5:52 AM (GMT-05:00)
To: "OWFS (One-wire file system) discussion and help"
<owfs-developers@lists.sourceforge.net>
Subject: Re: [Owfs-developers] Calibration of DS18B20 sensors?
You have to connect it and read the ID.
On 06/04/14 23:05, Joris Meijerink wrote:
> Hi,
>
> Anybody here tried to calibrate the 1-wire temperature sensors
> additional to the factory calibration? Only reference I've found sofar
> is this one:
> http://yosemitefoothills.com/Thermometers/ThermometerCalibrations.html
>
> At the moment I've got 30 DS18B20 measuring inside a glass jar in a
> little box of polystyrene foam with water and ice. Connected to a
> Raspberry Pi which takes a measurement of all the sensors every 2
> minutes. This takes about 30 seconds. After 8 hours the water is still
> pretty cold in a room which is approximately 20°C. Measurements:
> http://nl.tinypic.com/r/2mz9wed/8
>
> The results are a little spiky. That's probably the resolution of the
> sensors? Can this be changed? Or do I have to take an average over 5
> measurements the smooth things a bit?
>
> When using the average of the 30 sensors as being the "true"
> temperature, I can use regression analysis to compensate each sensor.
> Sofar i've found that linear regression (-0,04 / +0.06) gives me a
> better fit then quadratic regression (-0,14 / +0,25). Probably because
> of the small range of the temperature at the moment.
>
> Linear: http://nl.tinypic.com/r/2u8ur1w/8
> Quad: http://nl.tinypic.com/r/23wpeme/8
>
> How can one identify the sensors? Is the id code written on the DS18B20
> itself? Or do I have to plug them in one at the time to ID them?
>
> Kind regards,
> Joris Meijerink
>
>
> ------------------------------------------------------------------------------
> _______________________________________________
> Owfs-developers mailing list
> Owfs-developers@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/owfs-developers
------------------------------------------------------------------------------
Put Bad Developers to Shame
Dominate Development with Jenkins Continuous Integration
Continuously Automate Build, Test & Deployment
Start a new project now. Try Jenkins in the cloud.
http://p.sf.net/sfu/13600_Cloudbees_APR
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers
------------------------------------------------------------------------------
Put Bad Developers to Shame
Dominate Development with Jenkins Continuous Integration
Continuously Automate Build, Test & Deployment
Start a new project now. Try Jenkins in the cloud.
http://p.sf.net/sfu/13600_Cloudbees_APR
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers
