PT100 and XTR105 application

[466576266]

hello,anyone. recently, i am working with the temperature sensor PT100. the temp range is 0-100 degrees celsius. and i want the output is 4-20mA. and i find that the XTR105 is a good selection for my project. i know how to calculate the value of the resistor. the datasheet has given me a lot of equation. but still i have some questions:

1: the word from the XTR105 datasheet "the XTR105 is available in DIP-14 and SO-14 surface-mount packages and is specified for the -40 degrees celsuis to +85 industrial temperature range", and i donnt understand the word clearly. and my understanding is that: the measure temperature range of PT100 is just -40 to + 85, but what i want to measure is 0-100, the desired temperature range(0-100) is beyond of the datasheeet temperature range(-45 to +85). i donnt know whether i am right.



2: From the datasheet, the IC output is 4-20 mA. that's to say, in the minimum temperature ,the output is 4mA, in the maximum temperature ,the output is 20 mA. but it doesn't

give the resolution. my mean is that: if the temperature is 50.1 degrees celsuis, what the XTR105 will output ?

i donnt konw whether you understand what i mean. looking forward to your reply.

thanks.

 

[ericgibbs]

hello,anyone. recently, i am working with the temperature sensor PT100. the temp range is 0-100 degrees celsius. and i want the output is 4-20mA. and i find that the XTR105 is a good selection for my project. i know how to calculate the value of the resistor. the datasheet has given me a lot of equation. but still i have some questions:

1: the word from the XTR105 datasheet "the XTR105 is available in DIP-14 and SO-14 surface-mount packages and is specified for the -40 degrees celsuis to +85 industrial temperature range", and i donnt understand the word clearly. and my understanding is that: the measure temperature range of PT100 is just -40 to + 85, but what i want to measure is 0-100, the desired temperature range(0-100) is beyond of the datasheeet temperature range(-45 to +85). i donnt know whether i am right.



2: From the datasheet, the IC output is 4-20 mA. that's to say, in the minimum temperature ,the output is 4mA, in the maximum temperature ,the output is 20 mA. but it doesn't

give the resolution. my mean is that: if the temperature is 50.1 degrees celsuis, what the XTR105 will output ?

i donnt konw whether you understand what i mean. looking forward to your reply.

thanks.

hi,
The temperature range -40 degrees celsuis to +85 industrial is for the XTR105 itself not the PT100 measurement range.
You would not mount the IC at the PT100 measuring position.
Look at page #9 of the XTR datasheet for the resistor values for 0Cdeg thru 100Cdeg

If you use the resistors specified in the Table, 0Cdeg will give 4mA and +100Cdeg 20mA.

 

[466576266]

ok, thanks for your relply. i know what to do now.