HM TDS 3 Meter Price - View Price on Amazon Here


We have been using the HM TDS meter for the over ten years for our window cleaning business. It is a fantastic little hand held TDS meter. Here is why we think that it is so good.


We make pure water using the a method of filtering the water and storing the water in a container until needed.

We then pump the water out of the container, in our case a water butt, into our vehicle. but does that mean that a hand held TDS meter like the HM meter can do everything that we need? Wouldn't we need an inline TDS meter to check the quality of the water as it moves from the RO filter unit to the DI vessel and then again on its way to the storage container. Wouldn't a handheld TDS Meter only be useful for dip testing the water in the container?


The answer is Yes! We love to use the handheld meter to dip test as shown here. However if you are on a budget and you want the best value from the start and you don't have the money at this stage to invest in inline TDS meters, then you can use the following method:


1) Grab yourself a glass. Clean the glass using water already filtered into the storage container.

2) Repeat above to ensure that any water left in the glass is pure water. Do not dry as any particles on your cloth may be left in the glass (you won't be able to see them)

3) Collect water for testing into the glass and dip the tda meter into the glass.

4) Read the display for your result.


If you need to use the hand held meter to check the quality of water in a container and the water level is too low to be able to read the display, then the HM TDS Meter has a 'hold' button. Remember though to clear the display before you take other readings!

The other technical data that you may need to know for pure water window cleaning systems is the weight of window cleaning water for your vehicle.  You can read our article how much does window cleaning water weigh per litre here