diff --git a/NodeManager.cpp b/NodeManager.cpp
index 8ceee8d2461728b4341cc2cb86c07e604d28738c..e220ccf77a6bcc178c1031d07d28b0290b7f7ef8 100644
--- a/NodeManager.cpp
+++ b/NodeManager.cpp
@@ -1479,6 +1479,12 @@ int NodeManager::registerSensor(Sensor* sensor) {
   return sensor->getChildId();
 }
 
+// un-register a sensor to this manager
+void NodeManager::unRegisterSensor(int sensor_index) {
+  // unlink the pointer to this sensor
+  _sensors[sensor_index] == 0;
+}
+
 // return a sensor given its index
 Sensor* NodeManager::get(int child_id) {
   // return a pointer to the sensor from the given child_id
diff --git a/NodeManager.h b/NodeManager.h
index 46d2fc64868384f7e84716455254eb7e8e166296..4eb5b89933c69e20a3193c2b917682a6e832df60 100644
--- a/NodeManager.h
+++ b/NodeManager.h
@@ -750,6 +750,8 @@ class NodeManager {
     int registerSensor(int sensor_type, int pin = -1, int child_id = -1);
     // register a custom sensor
     int registerSensor(Sensor* sensor);
+    // un-register a sensor
+    void unRegisterSensor(int sensor_index);
     // return a sensor by its index
     Sensor* get(int sensor_index);
     Sensor* getSensor(int sensor_index);
diff --git a/README.md b/README.md
index 9cdd59081043ba00a1e56b1520403d6b6c8df1bb..2284eb1d39c3698140632040b7cc69bd8d935dee 100644
--- a/README.md
+++ b/README.md
@@ -154,6 +154,8 @@ Node Manager comes with a reasonable default configuration. If you want/need to
     void setSleepBetweenSend(int value);
     // register a built-in sensor
     int registerSensor(int sensor_type, int pin = -1, int child_id = -1);
+    // un-register a sensor
+    void unRegisterSensor(int sensor_index);
     // register a custom sensor
     int registerSensor(Sensor* sensor);
     // return a sensor by its index
@@ -305,13 +307,13 @@ Each sensor class can expose additional methods.
 #### SensorThermistor
 ~~~c
     // resistance at 25 degrees C (default: 10000)
-    void setNominalResistor(int value);
+    void setNominalResistor(long value);
     // temperature for nominal resistance (default: 25)
     void setNominalTemperature(int value);
     // The beta coefficient of the thermistor (default: 3950)
     void setBCoefficient(int value);
     // the value of the resistor in series with the thermistor (default: 10000)
-    void setSeriesResistor(int value);
+    void setSeriesResistor(long value);
     // set a temperature offset
     void setOffset(float value);
 ~~~