diff --git a/demod/mod/rs41mod.c b/demod/mod/rs41mod.c
index a480a04..369ee86 100644
--- a/demod/mod/rs41mod.c
+++ b/demod/mod/rs41mod.c
@@ -499,13 +499,13 @@ static float get_Tc(gpx_t *gpx, ui32_t f, ui32_t f1, ui32_t f2) {
 // (data:) ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/radiosondes/
 // (diffAlt: Ellipsoid-Geoid)
 static float get_RH(gpx_t *gpx, ui32_t f, ui32_t f1, ui32_t f2, float T) {
-    float b0 = gpx->ptu_calH[0]/46.64; // empirical
-    float b1 = 0.1276;                 // empirical
+    float a0 = 7.5;                    // empirical
+    float a1 = 350.0/gpx->ptu_calH[0]; // empirical
     float fh = (f-f1)/(float)(f2-f1);
-    float rh = 100.0 * (fh-b0)/b1;
-    float T0 = 0.0, T1 = -30.0; // T/C
-    if (T < T0) rh += T0 - T/5.5;        // empir. temperature compensation
-    if (T < T1) rh *= 1.0 + (T1-T)/75.0; // empir. temperature compensation
+    float rh = 100.0 * ( a1*fh - a0 );
+    float T0 = 0.0, T1 = -25.0; // T/C
+    rh += T0 - T/5.5;                    // empir. temperature compensation
+    if (T < T1) rh *= 1.0 + (T1-T)/90.0; // empir. temperature compensation
     if (rh < 0.0) rh = 0.0;
     if (rh > 100.0) rh = 100.0;
     if (T < -273.0) rh = -1.0;
diff --git a/demod/rs41dm_dft.c b/demod/rs41dm_dft.c
index 7326545..b71cd3a 100644
--- a/demod/rs41dm_dft.c
+++ b/demod/rs41dm_dft.c
@@ -570,13 +570,13 @@ float get_Tc(ui32_t f, ui32_t f1, ui32_t f2) {
 // (data:) ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/radiosondes/
 // (diffAlt: Ellipsoid-Geoid)
 float get_RH(ui32_t f, ui32_t f1, ui32_t f2, float T) {
-    float b0 = calH[0]/46.64; // empirical
-    float b1 = 0.1276;        // empirical
+    float a0 = 7.5;           // empirical
+    float a1 = 350.0/calH[0]; // empirical
     float fh = (f-f1)/(float)(f2-f1);
-    float rh = 100.0 * (fh-b0)/b1;
-    float T0 = 0.0, T1 = -30.0; // T/C
-    if (T < T0) rh += T0 - T/5.5;        // empir. temperature compensation
-    if (T < T1) rh *= 1.0 + (T1-T)/75.0; // empir. temperature compensation
+    float rh = 100.0 * ( a1*fh - a0 );
+    float T0 = 0.0, T1 = -25.0; // T/C
+    rh += T0 - T/5.5;                    // empir. temperature compensation
+    if (T < T1) rh *= 1.0 + (T1-T)/90.0; // empir. temperature compensation
     if (rh < 0.0) rh = 0.0;
     if (rh > 100.0) rh = 100.0;
     if (T < -273.0) rh = -1.0;
diff --git a/rs41/rs41ptu.c b/rs41/rs41ptu.c
index bfd83c5..f21738e 100644
--- a/rs41/rs41ptu.c
+++ b/rs41/rs41ptu.c
@@ -794,13 +794,13 @@ float get_Tc(ui32_t f, ui32_t f1, ui32_t f2) {
 // (data:) ftp://ftp-cdc.dwd.de/pub/CDC/observations_germany/radiosondes/
 // (diffAlt: Ellipsoid-Geoid)
 float get_RH(ui32_t f, ui32_t f1, ui32_t f2, float T) {
-    float b0 = calH[0]/46.64; // empirical
-    float b1 = 0.1276;        // empirical
+    float a0 = 7.5;           // empirical
+    float a1 = 350.0/calH[0]; // empirical
     float fh = (f-f1)/(float)(f2-f1);
-    float rh = 100.0 * (fh-b0)/b1;
-    float T0 = 0.0, T1 = -30.0; // T/C
-    if (T < T0) rh += T0 - T/5.5;        // empir. temperature compensation
-    if (T < T1) rh *= 1.0 + (T1-T)/75.0; // empir. temperature compensation
+    float rh = 100.0 * ( a1*fh - a0 );
+    float T0 = 0.0, T1 = -25.0; // T/C
+    rh += T0 - T/5.5;                    // empir. temperature compensation
+    if (T < T1) rh *= 1.0 + (T1-T)/90.0; // empir. temperature compensation
     if (rh < 0.0) rh = 0.0;
     if (rh > 100.0) rh = 100.0;
     if (T < -273.0) rh = -1.0;