Sensors and Probes


A wide variety of EM-compatible sensors is available, including weather, soil and various additional types of pressure/flow/level sensor and sourced both from Davis and from many other manufacturers.

Sensor range

Sensors other than ISS units must all be wired to a node. (Davis VP2 ISS units are currently a special case; an ISS unit is cabled to an EM gateway.)

The list of node-compatible sensors includes all Davis supplementary sensors (except ISS units and anemometers). In addition, a wide range of soil-monitoring sensors from other manufacturers has been tested and approved, as have sensors for water level and irrigation monitoring.

EM is designed to be adaptable in principle to additional sensor types (provided these are electrically compatible with the EM node interface) and so we fully expect that still more sensors will be approved for use in the future.

EM-compatible sensors fall into two groups: Davis weather sensors and third-party sensors, as detailed below:

Davis sensors

GroWeather ISS
GroWeather ISS

The proven range of Davis weather sensors can be used in an EM system, including also the soil sensors that are currently available from Davis, such as the Watermark soil moisture sensor and the leaf wetness sensor. There are some rules around weather sensors:

  • The simplest option for adding weather sensors to an EM system is to attach a cabled ISS to a gateway. (NB For now, ISS units should be cabled to a gateway and not to a node);
  • Wind speed/direction monitoring is via an anemometer attached to an ISS;
  • Supplementary temperature, temp/hum and rain gauges can all be cabled to nodes and there is no restriction on the numbers of such sensors in an EM system;
  • Third-party rain gauges are also likely to be fully compatible with EM, provided their interface is the same as the Davis units, ie contact closure to indicate a rain tip and an increment of 0.01″ or 0.2mm;

We do expect that system configurations for weather sensors will become even more flexible in the coming months.

NB Please remember that existing Davis wireless VP2 parts are not compatible with EM, because a different wireless protocol is used. In the EM system all sensors are cabled to a node or gateway.

Third-party sensors