GW-200 Handheld Temperature Reader

GrainWatch™ GW-200 is a hand-held temperature reader that is part of the temperature monitoring range. It is intended for silos and plain storage with a basic monitoring solution without network controller and PC connection.

How to use the GW-200

The GW-200 is easy to use. Just plug into a separate cable or a group (with network switch), press any of the two buttons and temperatures shows on the backlit display. Power comes from two standard AA batteries.


The GW-200 reads up to 32 sensors per sampling cycle and access point. More than 32 sensors require multiple access points. Both cables and spears apply to this.

As the GW-200 is only battery powered, the solution does not need ATEX-approval. However, all equipment other than the GW-200 is part of our ATEX – program and has undergone all necessary testing. See our certificates.


GrainWatch GW-200 interfaces directly with GWSL1100 or GWSL2100 temperature cables, separately or as a group (with GWNET). These hang from the silo roof. Standard sensor spacing is 2 m or 3 m and each access point is limited to:

  • 32 sensors in total
  • 200 m maximum cable length (including the temperature cables)
  • max 4 temperature cables per access point


When used in flat storage, the GW-200 preferably interfaces with temperature spears GWTL-R of the GrainWatch product range. Multiple spears can be daisy chained and connected to one access point. Every access point is limited to:

  • 32 sensors in total
  • 200 m maximum cable length (including the temperature spears)
  • max 10 temperature spears per daisy-chain.

As with temperature cables, it is necessary to program the sensors inside the temperature spears in one continuous sequence from sensor no. 1 – 32, since every sensor ID needs to be unique.
(e.g. spear 1: sensors 1-3; spear 2: sensors no. 4-6; spear 3: sensors 7-9, etc.). The temperature spears do not need to have the same amount of sensors.

Rugged handheld temperature monitoring unit with two intuitive buttons and backlit display. Enables easy handling and reading, even in dimmer locations.

The reader is connected via its 3.5 mm plug. At the push of a button you get the temperature readings from all sensors, from the bottom to the top. After reading the temperature values, the GW-200 automatically displays the sensor with the highest temperature value. The buttons enable scrolling between sensors.

Runs on two AA-type batteries.

Upgrading the Grain-Watch system from a hand-held to PC or mobile app is easy — the modular configuration and the use of the same high quality digital sensors in both cables and lances make expansion easy.

Since the GW-200 interfaces to the same type of digital sensors used in all GrainWatch equipment, upgrading to an automatic system is easy. Systems using the GW-200 are not ATEX-approved, but upgrading to an automatic system ensures ATEX compliance.

Type name: GW-200 handheld temperature reader. Interfaces with temperature spear GWTL-R and temperature cables GWSL1100 and 2100.
Dimensions: 200 mm x 95 mm x 40 mm
Weight: 240 g (including batteries)
Material: ABS
Power: 2 x standard AA size batteries
Battery life: Approximately 1 year
Operating temperature: -20°C – +40°C