Checking antifreeze used to be simple - just check the freezing point! Now with some modern EV cooling systems there is a need to measure the conductivity of the coolant. Many BEV & hybrid vehicles use a special antifreeze that is not diluted and is manufactured to have a very low conductivity. Over time coolant can be lost in leaks etc; what should happen is the coolant is replaced with the correct neat mix. Unfortunately, drivers and some less aware garages will top up with water which can result in conductive coolant coming into contact with live electrical systems with disastrous results. The Laser 9204 Conductivity tester has been introduced to allow the user to quickly check the conductivity of the coolant.