Installing Mopeka gas sensor to underslung tank

[PhilipLh]

My hopelessly inaccurate gas gauge in my Burford has given up the ghost and now reads empty all the time. I thought i would install a Mopeka pro check sensor as they are considerably more accurate. My concern is how to attach it safely to the underslung tank. The instructions just say to attach it with the magnets and with sonic gel on the sensor but the magnets are nowhere near man enough to keep it in place on an external tank. Also, the external tank is cylindrical and the sensor is flat so there is little contact with the surface, and the surface of the tank is treated/coated - presumably to prevent rust.

my initial thought was this:

https://www.etsy.com/uk/listing/1726210625/mopeka-pro-propane-tank-sensor-cover?dd_referrer=https%3A%2F%2Fwww.google.com%2F&variation0=4535156609

However they are out of stock. I thought a more permanent solution would be to attach a stainless steel disc to the bottom of the tank with epoxy and then mount the sensor on this with the mopeka universal collar which sticks on and holds the sensor in a clip. My concern is - do i need some sort of cover to provide protection from dust and road spray? Also should i put a silicone disc under the mount to reduce vibration or would this interfere with transmission of the sensor?

How have others attached this sensor safely to an underslung tank and how is it protected?

 

[Two on Tour]

My hopelessly inaccurate gas gauge in my Burford has given up the ghost and now reads empty all the time. I thought i would install a Mopeka pro check sensor as they are considerably more accurate. My concern is how to attach it safely to the underslung tank. The instructions just say to attach it with the magnets and with sonic gel on the sensor but the magnets are nowhere near man enough to keep it in place on an external tank. Also, the external tank is cylindrical and the sensor is flat so there is little contact with the surface, and the surface of the tank is treated/coated - presumably to prevent rust.

my initial thought was this:

https://www.etsy.com/uk/listing/1726210625/mopeka-pro-propane-tank-sensor-cover?dd_referrer=https%3A%2F%2Fwww.google.com%2F&variation0=4535156609

However they are out of stock. I thought a more permanent solution would be to attach a stainless steel disc to the bottom of the tank with epoxy and then mount the sensor on this with the mopeka universal collar which sticks on and holds the sensor in a clip. My concern is - do i need some sort of cover to provide protection from dust and road spray? Also should i put a silicone disc under the mount to reduce vibration or would this interfere with transmission of the sensor?

How have others attached this sensor safely to an underslung tank and how is it protected?



View attachment 1132355

Here is my solution, that has kept my Mopeka sensor safely in place for the past 6 years.

This is my earlier Mopeka standard sensor fitting to my underslung tank. I changed over to the Pro version when they came to market, and it mounts in the same way and position.
Sensor mounted on the tank with its magnets, but not wanting it to fall off if I hit a pothole, so I made a cover to hold it in place and give it some protection from road spray.
I found that the best position was to mount it is just to the left of the casing that contains the valve and unions, when looking at the casing as it then misses the tank's internal float gubbins.

The sensor is flush with the tank mounting brackets, that's a bit handy.

1mm thick aluminium cover trial fitted and ready to paint.
One end is bent over to grip the tank mounting frame and I just used a self tapper on the other end to fix it in place.
The clamp was only used to hold the cover in place to test that the cover fitted okay.

 

[PhilipLh]

Many thanks - that looks great!

Sadly I don't have suitably placed mounting frame with the right spacing but I may be able to adapt something. how do you stop the sensor sliding under the bracket or is it a tight fir?

 

[Jev88]

I've used this for four years.

 

[PhilipLh]

yes that could work - thank you!
How do you compensate for the curve of the tank? doesn't the flat sensor rock from side to side - how do you keep it square to the tank?

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[PhilipLh]

OK - so this is my eventual solution!

The tank is horizontal and has quite a small radius and hence a big curve.

The first thing to do was level the van so that the reading was true. I then applied some of the supplied dielectric grease to the sensor and just attached the Mopeka to the tank with the magnets to find a suitable position where it worked and I got a good reading. Tanks invariably have some gubbins inside (floats, baffles etc) that interfere with the readings in some positions. Once a suitable spot was found I applied a bit more dielectric grease to ensure good contact and then placed the Mopeka in its final position. The correct level can be found using a spirit level as it has a much more responsive than the app which has a significant time lag.

I then applied exterior silicone sealant all around the Mopeka and especially in the gap created because of the curve in the tank. This not only sticks the Mopeka to the tank it also seals and fills the gap effectively and provides some cushioning against vibration. It also seals all around the Mopeka so none of the dielectric grease can get washed out by road spray etc.

As a final belt and braces I put a velcro belt around the whole tank once the sealant had cured (24Hrs) to keep things in place. Hopefully this should stay in place over the harshest bumps. The sealant can be removed with a sharp knife when the battery needs replacing and the process repeated.

Hope this is helpful to anyone else with the same problem.