TMP007EASYCALEVM: Question about default values

NAOKI AOYAMA

Guru 11215 points

Part Number: TMP007EASYCALEVM

Hello,

Our customer estimate the TMP007 using the EasyCalEVM.

After Reinitialize, the value of the coefficient are as follows.

A1=0.00175

A2= -1.678E-5

C2=13.4

and others are default values.

Are these coefficient written to the coefficient registers of the TMP007? or all coefficient registers are

default values (A1=9.995E-4, A2=-6.020E-6, C2=0) ?

Because I can not read the registers, could you tell me a default condition?

Best Regards,

Naoki Aoyama

over 8 years ago

0 Jose Arteaga4 over 8 years ago

TI__Expert 5695 points

Please check the "How to calibrate?" section on the IR Temp Sensing FAQs post using the link below:

e2e.ti.com/.../548824

0 NAOKI AOYAMA over 8 years ago in reply to Jose Arteaga4

Guru 11215 points

Hello Jose,

Thank you for your reply.
I checked the FAQs but I can not understand.
I want to know why the initial coefficient and default value are different.
The EasyCal doesn't change the value of A1,A2 and C2.
How was the value determined?

Best Regards,
Naoki Aoyama

0 Ren Schackmann over 8 years ago in reply to NAOKI AOYAMA

TI__Mastermind 43775 points

The coefficients can be read on the Coefficients tab of the software. You can also write to these registers on this tab, but they will not be retained after power-cycle. The only way to modify the coefficients permanently is to use the Store bit of the Memory Access Register (page 35.) The EasyCal software doesn't have this capability.

Ren

0 NAOKI AOYAMA over 8 years ago in reply to Ren Schackmann

Guru 11215 points

Hello Ren,

Thank you for your reply.

I have one more question.
The customer want to extract coefficients of A1,A2 C2, TC0 and TC1.
What kind of information does it need to calculate these coefficients?
emissivity, FOV, distance from TMP007 to object.....

Best Regards,
Naoki Aoyama

0 Ren Schackmann over 8 years ago in reply to NAOKI AOYAMA

TI__Mastermind 43775 points

We calibrate the coefficients empirically. The EasyCal software collects data for this purpose, and performs calibration of S and B coefficients. We don't recommend changing A or C coefficients. The TC coefficients tune the transient correction feature, and must be calibrated using a stream of temperature change data with consistent read timings. The EasyCal can't support adjustment of TC coefficients for this reason. You can use attachment to evaluate the effect of all coefficients.

Ren

TMP007 Calibration Example.xlsx

0 NAOKI AOYAMA over 8 years ago in reply to Ren Schackmann

Guru 11215 points

Hello Ren,

Thank you for your giving the useful file.
I will use this file and evaluate coefficients.

Thanks,
Naoki Aoyama

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TMP007EASYCALEVM: Question about default values