add inHG pressure unit

1 files changed, 10 insertions, 0 deletions

diff --git a/unit.c b/unit.c
index d1e487d..dfe75c4 100644
--- a/unit.c
+++ b/unit.c
@@ -85,6 +85,11 @@ psi(double x) {
 	return x * KG_PER_LB * G / pow(M_PER_IN, 2);
 }
 
+Pressure
+inch_mercury(double x) {
+	return x * 3386.389;
+}
+
 double
 as_pascal(Pressure x) {
 	return x;
@@ -110,6 +115,11 @@ as_psi(Pressure x) {
 	return x * pow(M_PER_IN, 2) / (KG_PER_LB * G);
 }
 
+double
+as_inch_mercury(Pressure x) {
+	return x / 3386.389;
+}
+
 
 Temperature
 kelvin(double x) {