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Thursday, March 15, 2012

Am I Full or Empty? RV Monitor Panel and Sensor Updates

My Monitor Panel
The woes of RV monitor panels. Why can't we get a retrofit-able panel to match the size and shape of the original? Most panels from the '80s through the mid '90s are around the same size, maybe even earlier. Then there are the ones mounted in the stove/cooktop vent hood.

It seems simple to me that a company would want to manufacture something newer and better with the ability to use better sensors that would fit in the same space. As everyone knows, these things fail A LOT.

Wouldn't it make sense for some enterprising company to create a retrofit kit that would fit in the existing opening?? With generator switch/hour meters, water pump switch, water heater switch, etc. as well?

We have MUCH better sensor technology now that give much more accurate readings, but you have to add it someplace else???? Seems silly to me. I'd like to use the original space provided to mount a new monitor panel, that would allow me to access the new technology sensors.

My Panel "Guts" At Least It Has LEDs!
It certainly isn't related to the size of the electronics. The new stuff would likely take up far less space than the original. Simpler/less wiring too!

In my RV, I have already replaced a burned out one once, and that was really difficult to find!

I've tried to contact the various manufacturers, but they don't respond. I will keep trying as I believe there is a market for this product. I see many retrofits available now, that use the newer sensor technologies, but they are designed to be installed in another location. Either surface mounted or by cutting out a section of wall (or other "convenient surface") Personally, I don't like cutting into my RV unless I absolutely have to. Yes, I've done it...sometimes even successfully...but I didn't enjoy it!

Let's take a look at some of the newer technology sensors available now:

Capacitance Sensor
First is the Capacitance type. It uses the electrical capacitance of the liquid in the tank, measured through the tank wall, to determine the level. It is accurate to within two percent and the system that uses it will display a numerical percent of the tanks level, either full or empty. The main issue I have with this system is the display is an L.E.D. Like the old fashioned versions you need to push a button to display the level of each tank separately. At least my old one let me see all the levels simultaneously, although with a LOT less accuracy tan two percent.

They are INCREDIBLY easy to install as long as your tanks are no more than 24 inches high. You simply clean the side of your tank VERY WELL, then remove the backing of the self adhesive sensor and stick it on.

For tanks taller than 12 inches then you'd use two, one on top of the other. They can be cut to the correct size if your tank is shorter than 12 inches. Done. Well, almost. I would probably figure out some way of covering the exposed sensor back, maybe a piece of EPDM tape or spread some silicone over it. Seems to me the harsh outdoor environment mixed with road crud would do them in after a while. Unless, unlike me, you have tanks INSIDE of a bay or somehow sealed from the elements.

To wire these to the display is VERY easy. only two wires need to be run back to the display for ALL of your sensors. There is also a brand that uses a different type of capacitance sensor, but can be retrofitted using the original "through tank" sensor locations/holes. It is limited to the "Empty 1/4 1/2 3/4 Full" display, similar to the old monitor panels. In my world I like a bit more information than that, though it would be far more accurate at those tank levels and not susceptible to the "crud" fouling that plagues the original "through-tank" sensors.

Pressure Transducer Sensor
The next new technology sensor is a bit different. It uses a pressure transducer to measure the tank level. Once installed, you fill the tanks to the level you want reported as EMPTY then press a button. Then you fill the tanks to the level you want reported as FULL and press a button. The system can now display the tank levels based upon the pressure of the liquid on the transducer.

The installation is straightforward, but requires a hole at the base of the tank for the sensor. Not my favorite method, especially if I can get away with NO holes! Less chance of stuff leaking out. The display for this system will display from EMPTY to FULL in 1/8 increments. Not really all that better than the original, but likely more accurate! It's wiring is pretty straight forward, and uses telephone jack style connectors.

My personal preference in a system would be to utilize the strip style capacitance sensors, made more weather resistant, with an L.C.D. display that reads out percentages AND a bar graph for each tank. It should include LP, black, grey and fresh water as well as housing switches to turn on the water pump, water heater and start/stop the generator.

I can re-use the old mechanic HOBBS meter (hour counter for the generator) if there was a way to have the cutout done easily. Otherwise, put one in at the manufacturer! It should be available configured for some of the more common sized locations that were in general use. It shouldn't use much/any power. I would be okay with having to press a button to see all the bar graphs and perhaps a button for each numeric percentage display. This CANNOT be that tough to do! There must be a larger consumer market for something along these lines.

If you are interested in seeing someone make this, let me know! I can badger the manufacturers into coming up with a solution! I don't give up easily.

Be Seeing You... Down The Road,

Rich "The Wanderman"
http://www.thewanderman.com

16 comments:

  1. A popular upgrade/replacement (which still doesn't solve the "fitting in old space problem" is the SeeLevel sensor system that gives a far more informative report of the status of your tanks vs the old basic LED displays that most RVs have.

    http://www.rvgauge.com/rv.htm

    ReplyDelete
    Replies
    1. Big Matt,
      I usually don't identify brands in my articles since I'd like to stay neutral. I would mention that I use something personally and it works. Maybe that has some value with a vendor????
      Maybe we can convince SeeLevel to do a retro style version?

      Rich "The Wanderman"

      Delete
  2. Hi, thanks for the info. Do you have any websites to share regarding the supplier of the capacitor strip sensors?
    Jim, Ontario Canada

    ReplyDelete
    Replies
    1. Jim,
      You can buy the sensors from various online electronics vendors (DigiKey, etc) but you will need a control and display system as well.

      Rich "The Wanderman"

      Delete
  3. Industrial sensors have been available for years that give a digital readout. When I bought my first camper I was shocked that the technology was so far behind. Mind you, I didn't try to do anything about it..

    ReplyDelete
    Replies
    1. Bill,
      There are many technologies that have been around for a long time and are quite mature that would work well in the RV environment. Manufacturers need to hear that we WANT them! Otherwise we'll have the same appliances, power systems and accessories forever. I know, "If it ain't broke, don't fix it!" That may be true, but there is no shame in moving to a better mousetrap.

      Thanks,

      Rich "The Wanderman"

      Delete
  4. Just wondering if allot of these systems you talk about have been designed with the beating and banging and bouncing around that comes with RVing. That could have a big bearing on how long a system lasts and may be a reason as to why manufacturers are reluctant to change them. Let's face it, when looking for a new or used RV, MOST people research what they are looking at/for and those units with failing, faulty systems are usually not considered.

    ReplyDelete
    Replies
    1. Rick,
      After many years of over the road testing with the old style systems, it is obvious that something better is needed, both from an accuracy and a longevity standpoint. The newer systems have been around for quite a few years now, and since the are electronic rather than mechanical SHOULD last as long if not longer. All of the sensors and displays I've seen were designed for the RV market, so they should be OK.

      Rich "The Wanderman"

      Delete
  5. The biggest problem with updating are the multiple meters/displays that are needed. It doesn't take too many upgrades to get to the cost of a small PC screen. Thoughts?

    ReplyDelete
    Replies
    1. Anon,
      It would be great if there was an economical multisystem central display system available. Power, Tanks, etc. But the cost right now is prohibitive AND the retrofit would involve a lot of work.

      Maybe soon?

      Rich "The Wanderman"

      Delete
  6. I installed the SeeLevel gage (digital percentage readout) and it was not a trivial task. I had to cut off the bottom of a shared panel, trim and re-paint the remaining piece (generator control), then build a new (textured ABS) main panel and mount the old panel piece and the new SeeLevel panel in it. A lot of work, but the result looks really good and of course everything works so much better.

    ReplyDelete
    Replies
    1. Unknown,
      I agree the system will work MUCH better, but the work needed to make it a smooth looking install is troublesome. That's why I'd like to see one that will replace some existing shapes, monitor panels.

      Rich "The Wanderman"

      Delete
  7. Another option is an ultra sonic sending unit. It bounces sound waves into the tank from the top and measures how much time it takes to reflect off the liquid. I have stainless steel tanks, which makes my options for tank monitors more limited compared to plastic tanks.

    ReplyDelete
    Replies
    1. Ben,
      Hmmm. Interesting. I like the concept, but not so sure about the execution. Do you have more info? I'd like to do some aditional research.

      Rich "The Wanderman"

      Delete
  8. Hi, Rich,
    I appreciate your effots. I, too, would like to see something like the strips be adoped. I can't believe the manufacturers like Tiffin who are so obvlivious to such a positive change. I have a 2007 Bus and would like to change its tank monitors to something more functonal.
    Regards

    ReplyDelete
  9. Anon,
    I couldn't agree more. Many of my projects would be great additions or replacements for new coaches. The company's do not seem to be interested in working toward a better product. Just reducing cost.

    Sad really.

    Rich "The Wanderman"

    ReplyDelete

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