Home made Manometer


New member
I just got my cv1800 installed and ducted over to my table saw. I purchased the year end deal so it has a 16" impeller. So maybe its a cvmax. Anyways, I also installed a home made manometer so that I can tell when I need to clean my filters. I got the plans for it from the following link:


Towards the end of the video he says when the difference in the water level is about 2.5" you need to clean your filters. I noticed though while testing that for every blast gate I opened the difference in water level increased. So, the question is: How many blast gates should I have open to know when I need to clean the filters? Or is it simply a matter of marking the difference with one gate open and comparing the difference later on with the same gate?

On a separate note. When cleaning the filters, has anyone tried hooking up a small DC to the clean out box to suck the air out while blowing from the outside with compressed air?
I would recommend that you standardize on your pressure observations in order to get consistent trends in pressure change -- for example, with your new filters and ductwork installed, observe the pressure when the closest blast gate is open and make all subsequent observations with the same configuration. Keep a written record of your observations and you should be able to make an informed decision when to clean the filters. I would also check that the level of the fluid does not change due to evaporation through the open end of the tube so your comparisons are made with the same amount in the system. Consider using colored mineral oil versus water since you are not seeking absolute differences in inches of water.

For filter cleaning, I have read that folks use a 4" hose connected back to a blast gate on the ClearVue to recycle the dust from the filter cleanout back through the cyclone and into the bin. Others have used a smaller DC to perform the same task. Be careful in using compressed air to clean the filters -- I use an electric leaf blower that blows a broader stream of lower pressure air and it seems to work well.

Hope your bin sensor works well, too! We'd all love to see pictures of your installation.
Thanks for the ideas McRabbet! I'll take note of the difference in water level, not necessarily the level it reaches in case of evaporation or if I were to move the entire unit.

I took a before pic of the system I had before. It was pretty sad! When I get done with all the duct work I'll post some pics in the gallery.

As for the bin sensor, was I suppose to get one with the package deal!?!