add warning to conditioning

README.md

@@ -60,6 +60,14 @@ the following pins to connect your SGP41:
       ...
       ```
 
+## Conditioning
+
+After each restart of the sensor or when the hotplates have been switched off, the conditioning command must
+be called from idle mode. The conditioning heats the hotplate of the NOx pixel to a different temperature compared
+to the measurement mode enabling a faster switch-on thereafter.
+
+It is recommended to execute the conditioning for 10s, but **10s must not be exceeded** to avoid damage to the sensing material.
+
 ## Troubleshooting
 
 ### Initialization failed

sgp41_i2c.h

@@ -52,6 +52,9 @@ extern "C" {
  * different temperature for conditioning. This command returns only the
  * measured raw signal of the VOC pixel SRAW_VOC as 2 bytes (+ 1 CRC byte).
  *
+ * WARNING: To avoid damage to the sensing material the conditioning must not
+ * exceed 10s!
+ *
  * @param default_rh Default conditions for relative humidty.
  *
  * @param default_t Default conditions for temperature.

sgp41_i2c_example_usage.c

@@ -78,6 +78,8 @@ int main(void) {
     }
 
     // SGP41 conditioning during 10 seconds before measuring
+    // WARNING: To avoid damage to the sensing material the conditioning must
+    // not exceed 10s!
     for (int i = 0; i < 10; i++) {
         uint16_t sraw_voc;