diff --git a/lib/bs412.c b/lib/bs412.c
index 830963e..100757d 100644
--- a/lib/bs412.c
+++ b/lib/bs412.c
@@ -11,8 +11,12 @@ float measure_mpx(MPXPowerMeasurement* mpx, int deviation) {
 	mpx->i++;
 	float modulation_power = mpx->sample/mpx->i;
 	if (mpx->i >= mpx->sample_rate) {
-		mpx->sample = 0.0f;
+		mpx->sample = modulation_power;
 		mpx->i = 0;
 	}	
 	return modulation_power;
+}
+
+float dbr_to_deviation(float dbr) {
+	return 19000.0f * powf(10.0f, dbr / 10.0f);
 }
\ No newline at end of file
diff --git a/lib/bs412.h b/lib/bs412.h
index 6338bbe..2167f55 100644
--- a/lib/bs412.h
+++ b/lib/bs412.h
@@ -11,3 +11,5 @@ typedef struct
 void init_modulation_power_measure(MPXPowerMeasurement *mpx, int sample_rate);
 
 float measure_mpx(MPXPowerMeasurement *mpx, int deviation);
+
+float dbr_to_deviation(float dbr);