Environmental Monitor (EM) Sensors

Samsara EM-series sensors are ideal for monitoring food safety during transportation, warehouse conditions, and other applications that rely on environmental data to ensure quality or maintain compliance.

Warning

Samsara EM sensors are not intended to be used as a primary method of detecting fires or monitoring life threatening conditions.

The Samsara temperature monitors use thermistor-­based temperature sensors to monitor the temperature without the need for periodic re­calibration. After sampling the environment, the sensor delivers the new data to the Sensor Environment Report.

The table below summarizes the EM features by model:

EM Model	Feature Description
EM31	A wireless, waterproof, data logging temperature sensor. For a wider range of temperature applications, connect an ACC-EM-P1 accessory probe. The EM31 sensor uses a Sensylink CT7117 sensor which is factory­ calibrated and tested in a controlled environment. For more information, see the Certificate of Calibration which certifies each Samsara EM sensor has been calibrated to read temperature according to the specifications noted in the EM31 datasheet.
EM21 and EM22	The EM21 and EM22 are wireless, waterproof, data logging environmental monitors with temperature and humidity sensors. The EM21 and EM22 sensors use a Silicon Labs 7013 module which is factory­ calibrated and tested in a controlled environment. For more information, see the Certificate of Calibration which certifies each Samsara EM sensor has been calibrated to read temperature and humidity according to the specifications noted in the EM21 and EM22 datasheet.

Before you can begin using your EMs, Install an Environmental Monitor Sensor, then pair your sensor to start monitoring conditions from your Samsara dashboard.

Install an Environmental Monitor Sensor

Samsara supports different models of Environmental Monitor (EM) sensors to ensure quality and maintain compliance for various applications that rely on environmental data, such as food safety during transportation. To install an EM Sensor, follow the instructions for your model:

• EM31 Sensor

• EM21 or EM22 Sensor

Install an EM31 Sensor

To install an EM31 sensor, follow the detailed workflow below or for printable installation instructions, see the EM31 Install Guide.

To install an EM31 sensor, you will need:

1. Identify a mounting location within 100 feet of your gateway.

   To ensure accurate ambient and probe temperature, we recommend the following placement suggestions:

   • Ambient temperature: Place the device in a location with open airflow and away from doors to avoid large temperature fluctuations. Ensure the rubber plug on the bottom of the device remains inserted when the temperature probe is not in use.

   • Probe temperature: Ensure four inches below the device is free of obstructions to allow for cable connection.

     Note

     The probe is sold separately.

2. Mount the device using the attached adhesive strips onto a clean, flat surface.

3. Secure the sensor using the provided screws.

   

4. If applicable, install the probe.

   

   1. Remove the rubber plug at the bottom of the device.

   2. Insert the connector with the grips facing forward.

   3. Fasten the connector with the screws.

      An "EXT" external temperature reading will appear on the screen.

   Note

   Both ambient temperature and probe temperature will be displayed in the Samsara dashboard

5. Verify that the sensor is reporting the temperature from the Samsara dashboard.

Install an EM21 or EM22 Sensor

To install an EM21 or EM22 sensor, follow the detailed workflow below or for printable installation instructions, see the EM21 Install Guide.

To install an EM21 or EM22 sensor, you will need:

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 fasten with the top screw.

4. Verify that the sensor is reporting the temperature from the Samsara dashboard.

Sensor Troubleshooting

If you need to troubleshoot your Environmental Monitor sensor, refer to the following steps for your observed behavior.

Issue Observed	Troubleshooting Steps
EM31 Sensor Troubleshooting
Screen is blank due to low battery.	Replace the EM31 battery with an L91 Energizer ultimate lithium battery.
EM31 isn't reporting humidity.	This is expected as the EM31 does not have a humidity sensor.
No connection bars are showing in the upper right corner of the sensor.	Check that the gateway is powered and in full power mode or on periodic unpowered checkins. Ensure there is a powered gateway within range of the sensor, less than 100 feet away.
The report displays the wrong units (Celsius or Fahrenheit).	The units displayed on the sensor are based on the locale of the dashboard the sensor belongs to. Update the locale of your organization to change the unit of measurement. Caution When you update the locale of your organization, the unit of measurement will change for all devices in the Samsara dashboard.
EM21 and EM22 Sensor Troubleshooting
No temperature data is showing on the dashboard.	Ensure that the sensor is installed within 100 feet of the gateway. Remove the device from its mount and place it in close proximity to the gateway to regain connectivity. Check the signal strength on the display (hold down the display button) and make sure there are at least three bars. Press and hold the button to see connectivity while returning the device back to its mounting location. Look for physical damage, such as damage to the probe on EM22 or condensation on the display.
Humidity is reading at 100%.	Contact Support.
There is no display on the EM.	Press on the display button for three seconds. If issue persists, contact Support.

Additional Environmental Monitor Installation Resources

For printable installation instructions, see the Environmental Monitor Install Guide.