Changeset 17395 for trunk

Timestamp:

11/27/13 16:18:24 (11 years ago)

Author:

tbretz

Message:

Finally updated the function for the Pt1000 to something which is almost exact within 5-25deg

File:

• trunk/FACT++/src/fscctrl.cc (modified) (1 diff)

trunk/FACT++/src/fscctrl.cc

@@ -93 +93 @@
     double GetTempPT1000(double R) const
     {
-        const double R0 = 1000; // 1kOhm
-
-        const double a = 3.893e-3;
-
-        return (R/R0 - 1)/a;
+        // This is precise within the range 5degC and 25degC
+        // by 3e-3 degC. At 0degC and 30degC it overestimates the
+        // temperature by 0.025 degC. At -10degC it is ~0.9degC
+        // and at 40degC ~0.05degC.
+        const double x = R/1000;
+        return -193.804 + 96.0651*x + 134.673*x*x - 36.9091*x*x*x;
+
+        //const double R0 = 1000; // 1kOhm
+        //const double a = 3.893e-3;
+        //return (R/R0 - 1)/a;
     }