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Temperature WS-2350

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Brutus_RST
Posts: 6
Joined: Wed 05 Sep 2012 12:43 pm
Weather Station: LaCrosse WS2350
Operating System: Windows 7
Location: Appingedam (NL)
Contact:

Temperature WS-2350

Post by Brutus_RST »

Hello,

Has anyone calibrated their WS-2350 with an analogue thermometer?
Mine is OK for temperatures above zero (maybe 0.1 degrees off), but when the temperature is below zero it is not OK.
I can calibrate the temperature in Cumuls. I have to give an off-set of -1 degrees and multiply it by 0,95, then it is OK again.
But then again, when the temperature is around or above zero, the temperature is too low and I have to remove the off-set.

I know it is not one of the most expensive sets, but maybe someone has ran into the same problem and found a solution for it.

Thanks in advance.
AllyCat
Posts: 1124
Joined: Sat 26 Feb 2011 1:58 pm
Weather Station: Fine Offset 1080/1 & 3080
Operating System: Windows XP SP3
Location: SE London

Re: Temperature WS-2350

Post by AllyCat »

Brutus_RST wrote:I have to give an off-set of -1 degrees and multiply it by 0,95, then it is OK again.
Hi,

That doesn't seem to be the correct type of correction factor because it will give a "discontinuity" around zero (or wherever you switch back to the correctly calibrated part). Can you give a few examples over the range of your "actual" and "measured" temperatures?

Probably all "good quality" stations will use a dedicated, factory-calibrated temperature sensing integrated circuit, connected by a one or two wire digital data bus (I2C, SPI, etc.) and there is nothing you can do except identify the device and fit another which might be better (or specified to a higher accuracy).

However, most of the Fine Offset models (WH 108x, etc., but apparently not 308x) use a thermistor (I don't know about the La Crosse brand) which it might be possible to calibrate (better) by adding a suitable resistor in series or parallel (or both) with the thermistor. The FO thermistor can be seen in the "Photos of the insides...." thread here.

But IMHO you're probably expecting too much accuracy from a relatively "cheap" station.

Cheers, Alan.
Brutus_RST
Posts: 6
Joined: Wed 05 Sep 2012 12:43 pm
Weather Station: LaCrosse WS2350
Operating System: Windows 7
Location: Appingedam (NL)
Contact:

Re: Temperature WS-2350

Post by Brutus_RST »

But IMHO you're probably expecting too much accuracy from a relatively "cheap" station.
Yes, I also do think myself.
I do not have a list of measurements. I will keep track of this.

When I have some spare time, Ill try to see what kind of parts is used in the 2350 for measuring and try to give it an update.

If I have an update, Ill post it here.

Thanks for the reply.
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