Scaling of thermocouples type K with KRYPTON-TH

Hello Slovenia,

Our customer is asking for the scaling polynoms you "really" use in the KRYPTON-TH hardware.

I know you use standard ANSI or IEC polynoms, can you send me the coefficients you use with the different temperature ranges ? This will help our customer trust the brand new hardware (KRYPTON and SIRIUS) we use.

Thanks for all !

Regards,

Dear Helmut O'Brian,

we would just like to inform you that the question was forwarded to our developers, we will send you an email as soon as we will have the information you need. 

Best regards.

Rok

Hi Rok !

No news ?

I just need this information for type K thermocouples...

Thanks,

Regards,

Dear Helmut O'Brian,

first I want to apologize for the late response.

I received an answer from our developers that we do not use polynomials, but we calculate from the tables with interpolation.  

#define PT1000_A_COEF 3.9083E-03  

#define PT1000_B_COEF -5.775E-07 

tc_channel[i].pt1000_T = (-PT1000_A_COEF +

             sqrt(PT1000_A_COEF*PT1000_A_COEF - 4.0*PT1000_B_COEF*(1.0-tc_channel[i].U32ADC_2 / ((sModuleSettings[i].dR_Pt1000_0C + 1) * tc_channel[i].U32ADC_3))))/

             (PT1000_B_COEF * 2);

             tc_channel[i].pt1000_T *= (sModuleSettings[i].Pt1000_gain_scale + 1.0 );

 CJC:       fPt1000_V = calculate_TC_voltage_from_table (tc_channel[i].pt1000_T, tc_type);

  i32md_T = tc_channel[i].U32ADC_1 - 0x800000UL;

  md_T = (sModuleSettings[i].calib_full_32_10_scale + 1.0 ) * tc_channel[i].AD_factor * i32md_T;

  md_T += fPt1000_V;

  md_T = calculate_TC_temperature_from_table (md_T, tc_type);

The linearization curve is calculated from this table:

https://es.omega.com/temperature/pdf/Type_K_Thermocouple_Reference_Table.pdf

Best Regards.

Rok

Thanks for your feedback Rok !

Customer will be happy !

Have a great day !