Environmental Monitor (EM) Sensors

The Samsara Environmental Monitor Sensors (EM21 and EM22) are a wireless and waterproof temperature and humidity sensor.  Samsara EM-series monitors are ideal for ensuring food safety during transportation, monitoring warehouse conditions, and other applications that rely on environmental data to ensure quality or maintain compliance.  

• The EM21 (monitor pictured on the left below) is a wireless, waterproof, data logging environmental monitor with temperature and humidity sensors. The EM21 has built-in sensors to detect: 
  • Ambient Temperature between ~40 and 60 Degrees Celsius (~40 to 140 Degrees F).
  • Relative Humidity between 0 and 95%.
• The EM22 (monitor pictured on the right below) adds an external temperature probe that measures temperature in liquids and extremely hot and cold environments. The EM22 uses an external probe to detect:
  • Temperatures between ~55 and 100 Degrees Celsius (~67 to 212 Degrees F). 

Both models of Environmental Monitors (EM21 and EM22) can withstand all types of weather conditions including rain, mist, snow, splashes, humidity, and dust exposure.  The EM21 and EM22 are IP67 waterproof rated, however, they are not designed for prolonged submersion. To monitor the temperatures of liquids, use the EM22, which has an external probe to measure the liquid temperatures.  You can also add a water-resistant silicone cover to protect the sensors in environments where prolonged humidity and moisture is common.  Each sensor runs for 3+ years using a single AA battery.  

Installing the Environmental Monitor (EM) Sensor

1. Identify a mounting location within 100 feet of your gateway. 
2. Secure the mounting plate of the sensor using the provided screws. 
3. Secure the sensor cover to the mounting plate and secure with the top screw. 
4. Verify that the sensor is reporting the temperature from the Samsara Dashboard. 

For more information, please view the Install Guide. 

Assigning Sensors to Vehicles

You can assign sensors to a specific vehicle gateway, so the sensors will only connect to and associate with that gateway. 

To assign a sensor to a gateway:

• Navigate to Settings (Gear Icon) > Sensors.
• Go to the Edit button next to the sensor you would like to assign. 
• Assign the sensor a unique name, if you haven't done so already, then pin sensor to a particular Gateway.
• Select Save. 

EM21 and EM22 Troubleshooting 

In the case that you need to troubleshoot your EM21 or EM22, here are some steps to take based on the behavior observed.

No temperature data is showing on the dashboard:

1. Ensure that the sensor is installed within 100 ft of the gateway.
2. Remove the device from its mount and walk it toward the gateway in order to regain connectivity.
3. Check the signal strength on the display (hold down the display button), and make sure there are at least 3 bars.
4. Press and hold the button to see connectivity while walking the device back to the mounting location.
5. Look for physical damage. ie. damage to probe on EM22, condensation on display, etc.

Humidity is reading at 100%: 

1. Please contact support for the next steps.

There is no display on the EM:

1. Press on the button for 3 seconds.
2. If still no display, please contact support for the next steps.