There is a wide variety of diesel meters available, with varying costs, flow rates and accuracies. It is important to select a meter that suits your requirements – you cannot select the cheapest meter available and then expect it to be super accurate and capable of handling high flow rates, as you are bound to be disappointed. Our approach is to leave the choice to the client.
The cheapest type of meter we can use, is the type that would normally be fitted to a diesel trailer. We have developed sensors for the Piusi meter (K33 and K44 models) and also for the Jerrycar meter. These meters are not very accurate – when new, their accuracy is specified to be within 1% of the real volume measured PROVIDED that the flow rate is kept between around 10 litres per minute and 80 litres per minute, and PROVIDED that they have been meticulously calibrated ex-factory. In practice we find deviations of up to 8% even on new meters. At very low flow rates (e.g. when you are doing the last few litres very slowly to get the tank completely full) you must accept that the meter will potentially be VERY inaccurate. These meters also cannot handle high flow rates – for these cases, you need to purchase a bigger (and typically much more expensive) meter. We do manage to obtain reasonable results with these cheaper meters, by making an adjustment in the software. This will result in a reading on the meter itself which is different from that shown on our electronic display. The difference is not an indication of something that is wrong per se, but rather that the electronic reading has been corrected to be in line with the actual volume passed.
If high accuracy is important to you, we can supply a meter similar to those fitted to garage type pumps, that you would see at a normal filling station. These meters are designed to be accurate from very low flow rates, and they typically do not lose accuracy as quickly with age. (They can also be re-calibrated from time to time). These meters cost a bit more than double the price of the cheaper types.
If you already have a garage type pump installed, this normally offers a reasonably easy and cheap solution, where we simply install a sensor that obtains the meter reading directly from the pump. It does not matter if the pump is old – there are businesses that can repair or rebuild these.