Problems with TGS2444(Amonia)

[Sharagim]

Hi,
I have a few questions about TGS2444.
1- How much will be heater temperature after some minutes.
2- There is something which I cant figure out in the datasheet, it mention 14ms high then low so it means in each 250ms it is only 14ms on ? So the temperature will be something like 30-40 centigrade and not to0 high?

 

[FvM]

The heater temperature isn't specified. Combining the heater parameters from the datasheet, I assume that the peak temperature is at least 150 °C (if the heater wire is pure metal, e.g. platinum).

 

[Sharagim]

As you can see it mention in 250ms cycle will be 14ms 4.8V, I dont know it means 4.8V to transistor base or to sensor. If I give sensor 14ms 4.8V then the temperature will be something like 30-40 degree.

 

[FvM]

If I give sensor 14ms 4.8V then the temperature will be something like 30-40 degree.

How did you come to know?

 

[Sharagim]

I measure by thermometer .
You think it is right to give 14ms 4.8V to heater ? or it should be 236ms on 4.8V?

 

[FvM]

I measure by thermometer

You mean the case temperature? That might be. I don't believe that you have a thermometer that is small enough to measure the heater temperature.

It's clearly only 14 ms on-time.

 

[Sharagim]

Yes, I mean case.
I tried both :
when I put 14ms in 250ms it is about 30-40 but when I set on 236ms then I cant touch the case.

 

[FvM]

Applying heater power for 236 ms will possible damage the sensor.