[sdiy] Measering KTY81-110

[HA.Synth at t-online.de]

Well,

if i look at my data and the datasheet of KTY81-110 there is something wrong. 
When the datasheet is right, what i asume,  then i have an constant error in 
my data or a bunch of bad KTY's. The error is +250R. But when i draw the 
lines and subtract the constant error i can see that they are close to the 
datasheet and pretty linear in the interesting range. Think i have to 
control/calibrate my tempsensor. Needs boiling water and ice. 

Harald


Am Donnerstag 25 Mai 2006 09:09 schrieb HA.Synth at t-online.de:
> Hi,
>
> I have measured some KTY181-110. I soldered them on banana jackets put
> cables in and let them hangout of my (Kitchen) ofen (My wife was out that
> evening). I hang them in the middle of the ofen as close together as
> possible to be shure that they have the same temperature. I als added an
> digital temp sensor to measure the temp. I started to warm them up in 5C
> steps. Doesn't work! Never trust the temp display of your kitchenofen! So I
> go: heating all up at 60C for about 20 minutes to keep all warm. Turn the
> ofen of and started measuring and waiting for the temp to go down. And
> waiting and waiting... Tooks about 3hours to go down from 55C to 28 C. 17,5
> and 19,5C was taken in my room. Guess where I measured the -18C?
>
> I can not guarantie for the absolut temp. It shoud bo within +<0,5C. But I
> a mpretty shure that all parts had teh same Temp when measuring
>
> Here wat i got deg in C R in Ohm
>
>
> c		1		2		3		4		5
>
> -18		7447	-----		-----		-----		-----
> 17,5		9717	9770	9773	9778	9729
> 19, 5		9888	9905		9881	9865		9851
> 28			10438	10445	10427	10415	10387
> 32,5		10730	10757	10739	10714	10683
> 34,5		10901	10929	10908	10885	10852
> 38			11219	11249	11228	11202	11169
> 41			11452	11481	11461	11436	11399
> 43,5		11702	11723	11691	11683	11647
> 46,5		11920	11992	11955	11944	11905
> 50			12347	12365	12314	12299	12261
> 55			12851	12870	12815	12785	12735
>
>
> So, now any cracks out there in the list to interpret that raw data?
> Does anyone do the same with tempcos?
> I have none yet so I can't do it. If anyone lent me some i can repeat the
> measuring. I'll send them back when I'm done.
>
> Harald