1) When am calibrating ltc2984 it showing temperature variation up to 10 degree plus or minus .
2) Sometimes suddenly temperature output is not getting it look like hanging condition .
3) Datasheet they mention ltc2984 accuracy is 0.001 but am not able to get one degree accuracy degree . it showing more than 3 degree error.
I will be glad to help you diagnose this issue. Could you provide some more information about your application?
What sensors are you using?
How are they configured?
If you are using thermocouples, what sensor are you using for the cold junction compensation - how is it thermally coupled to the thermocouple input?
Are you using the DC2399 or a custom PCB?
Are you using the GUI tool to record the data or another software?
How are you calibrating the temperature - in a temperature chamber or oil or water bath? How long are the leads? Is the PCB with the Rsense or CJC or LTC2983 in air or in a box?
The more information you can provide about your application the better I will be able to help you.
1) Am using thermocouples , for cold junction compensation BRN3904T41 ,am using custom pcb
2) Not using GUI tool and using Arduino software
3) in water bath only am calibrating the temperature and pcb kept it in box
4) Adopting DC2399A1-SCH for ltc2984 section reaming is Atmega328 micro controller
And bom allso DC2399A1-BOM
Thank you - the accuracy of the thermocouple channel will be dependent on the accuracy of the sensor itself, the cold junction sensor accuracy, and the error contribution of the LTC2984.
Diode-connected BJT are the least accurate cold junction sensor although they are inexpensive and can still be a good choice because they can be mounted as TO-92 parts in the cold-junction clip of many standard thermocouple jacks.
I would suggest trying to measure the non-ideality factor of the diode and see if that helps the accuracy - most 2N3904 transistors are between 1.003 and 1.004. You may also try 3-reading mode for the diode if your board has some series resistance to the diode.
Instated of diode RTD is showing better performance. When amusing pt100 sensor for room temperature compensation the accuracy issue i think almost solved.Now am getting +/- 2 degree only.I think this error can reduce by doing software calibration.
Is there any software calibration procedure for LTC 2984 ADC output? or any equation for calibration factor?.
if am masking the LSB bit then then, it will make any difference LTC 2984 output ?