As you will be aware, one of the requirements of WATO legislation is that the temperature and humidity of the compartment in which the horses travel is monitored, recorded and regulated for the comfort of the horses. If the temperature in the horse compartment rises above or falls below the comfort range for the horses, then steps must be taken to regulate it ( open or close vents, switch on air conditioning systems, etc).

1. Fix a normal garden thermometer (available from most garden centres) in the roof of the horse compartment, behind the horse's heads so they cannot reach it, and in a position where the Attendant would be able to see the temperature gauge . Record the reading in a log book at 15 minute intervals.

2. From 2009, it will be necessary to monitor and record humidity as well as temperature. The easiest and most economical way to do this is to fit wireless temperature and humidity sensors in the roof of the horse compartment, behind the horse's heads so they cannot reach them ( 1, 2 or 3 sensors would be needed, depending on the size of the horse compartment ? an articulated horsebox is likely to need at least 2 sensors; a 4 ? 6 horse rigid may only need one sensor). The main unit goes on the dashboard at the front of the vehicle. The main unit needs to be pre-set to record an optimum comfort temperature range for the horses. The sensors send a signal to the main unit, which constantly displays the readings, and gives either a visual (flashing light), or audio signal if the temperature goes outside the selected range.

They all have a range of 20-30m (60-90ft), so are suitable for articulated horseboxes as well as rigids. However, because horseboxes are constructed out of so many different materials, it is worth explaining what you want to use it for, and asking if they will take it back if your insulation, etc, inhibits the signal.

These are relatively inexpensive, and run on standard AA or AAA batteries.



This unit is available from The Weather Shop, but similar systems are manufactured by La Crosse and the Onset Corporation and sold on various ?weather monitoring? sites on the internet, and are probably available from local retailers.

The TFA Wireless Temp/Humidity Logger allows you to monitor conditions inside your horsebox from the cab. Alarms can be set to alert you about specific temperature and humidity levels and then the data is offloaded wirelessley to your PC to demonstrate conformance with WATO regulations.

  • Wireless communication via supplied usb dongle
  • Easy to deploy and offload
  • Reception range for the sensors up to 100 metres
  • Up to 50,000 temperature and humidity data logging intervals
  • 1% to 99% humidity indication (resolution 0.1 degree, accuracy + - 3%)
  • Visual and audible high & low alarm thresholds
  • Additional transmitters can be incorporated

It may be worth shopping around, but there seems little to choose between the prices of this type of equipment. Do be warned that there is some much cheaper equipment, which appears to do the same thing, but which may not work properly if the horse travelling compartment gets very hot and steamy. (Personally, we would strongly recommend taking the batteries out after each journey, letting batteries and units dry out thoroughly).


This information is published courtesy of the British Driving Society,
who are a DEFRA approved awarding body for the WATO Certificate of Competence.