diff --git a/bme280.html b/bme280.html
index 47c93ba..9aa998b 100644
--- a/bme280.html
+++ b/bme280.html
@@ -23,6 +23,12 @@
      <label for="node-input-extra"><i class="fa fa-check"></i> Extra Data</label>
      <input type="checkbox" id="node-input-extra" style="width: 60%;" />
   </div>
+
+  <div class="form-row">
+    <label for="node-input-preasure"><i class="fa fa-tag"></i> Topic</label>
+    <input type="text" id="node-input-preasure">
+  </div>
+
 </script>
 
 <script type="text/javascript">
@@ -38,8 +44,9 @@
         return v.length==4 && v[0]=="0" && v[1].toUpperCase()=="X" && !isNan(n) &&
         n>=0x10 && n<0x78;
       }},
-      topic: {value:'bme280', required:false },
-      extra:{value:false, required: true}
+      topic: { value:'bme280', required:false },
+      extra: { value:false, required: true},
+      preasure:{ value:1013.25, required: false, validate: RED.validators.number() }
     },
     outputs:1,
     inputs:1,
diff --git a/bme280.js b/bme280.js
index 23e3f95..ac7fdb0 100644
--- a/bme280.js
+++ b/bme280.js
@@ -11,6 +11,7 @@ module.exports = function (RED) {
         node.addr = parseInt(n.address, 16);
         node.topic = n.topic || "";
         node.extra = n.extra || false;
+        node.preasure= parseFloat(n.preasure) || 1013.25;
         node.initialized = false;
         node.isBME = false;
 
@@ -18,34 +19,28 @@ module.exports = function (RED) {
         node.status({ fill: "grey", shape: "ring", text: "Init..." });
         node.log("Initializing on bus" + node.bus + " addr:" + node.addr);
         node.sensor = new BME280({ i2cBusNo: node.bus, i2cAddress: node.addr });
-        node.sensor.init().then(function (ID) {
-            node.initialized = true;
-            node.type = ID == BME280.CHIP_ID_BME280() ? "BME280" : "BMP280";
-            node.isBME = (node.type == "BME280");
-            node.status({ fill: "green", shape: "dot", text: node.type + " ready" });
-            node.log("Sensor " + node.type + " initialized.");
-        }).catch(function (err) {
-            node.status({ fill: "red", shape: "ring", text: "Sensor Init Failed" });
-            node.error("Sensor Init failed ->" + err);
-        });
+        var fnInit= function() {
+            node.sensor.init().then(function (ID) {
+                node.initialized = true;
+                node.type = ID == BME280.CHIP_ID_BME280() ? "BME280" : "BMP280";
+                node.isBME = (node.type == "BME280");
+                node.status({ fill: "green", shape: "dot", text: node.type + " ready" });
+                node.log("Sensor " + node.type + " initialized.");
+            }).catch(function (err) {
+                node.status({ fill: "red", shape: "ring", text: "Sensor Init Failed" });
+                node.error("Sensor Init failed ->" + err);
+            });
+        };
+        // Init
+        fnInit();
         // trigger measure
         node.on('input', function (_msg) {
             if (!node.initialized) {
                 //try to reinit node until no sensor is found
-                node.sensor.init().then(function (ID) {
-                    node.initialized = true;
-                    node.type = ID == BME280.CHIP_ID_BME280() ? "BME280" : "BMP280";
-                    node.isBME = (node.type == "BME280");
-                    node.status({ fill: "green", shape: "dot", text: node.type + " ready" });
-                    node.log("Sensor " + node.type + " initialized.");
-                }).catch(function (err) {
-                    node.status({ fill: "red", shape: "ring", text: "Sensor Init Failed" });
-                    node.error("Sensor Init failed ->" + err);
-                });
+                fnInit();
                 return null;
             }
             node.sensor.readSensorData().then(function (data) {
-
                 _msg.payload = data;
                 data.model = node.type;
                 if (!node.isBME && _msg.payload.humidity !== undefined) delete _msg.payload.humidity;
@@ -56,7 +51,7 @@ module.exports = function (RED) {
                         pl.heatIndex = BME280.calculateHeatIndexCelcius(data.temperature_C, data.humidity);
                         pl.dewPoint_C = BME280.calculateDewPointCelcius(data.temperature_C, data.humidity);
                     }
-                    pl.altitude_M = BME280.calculateAltitudeMeters(data.pressure_hPa, 0);
+                    pl.altitude_M = BME280.calculateAltitudeMeters(data.pressure_hPa, node.preasure);
                     pl.temperature_F = BME280.convertCelciusToFahrenheit(data.temperature_C);
                     pl.pressure_Hg = BME280.convertHectopascalToInchesOfMercury(data.pressure_hPa);
                 }