Announcement

Collapse
No announcement yet.

Propane level monitoring with RD3 hall-effect sensor

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • deheacock
    replied
    Update/Background on Robertshaw/Centeron LP Tank Interface

    The Robertshaw rep returned my call yesterday. I learned a lot and offer it here for the record. Short version: Robust, industrial solution. A little pricey for us HS users and not without some development work to be done. Sounds almost perfect to me!

    BACKGROUND: Robertshaw "...developed the seamless metal bellows that became the precursor to the first home and automatic thermostats. During this same period of time, Fredrick Robertshaw invented the first water heater thermostat. These inventions served as the founding seeds for the company that is known today as Robertshaw Industrial Products." Robertshaw Industrial is now a part of Inventsys, PLC, a London based company. Centeron is a family of products developed by Robertshaw Industrial.

    MARKET: The Centeron family of products is designed to remotely monitor liquid storage tanks, including LP gas. Large industrial LP gas users with many tanks widely dispersed are the primary users and target market of this system. A good example is the poultry industry where a chicken farmer may have dozens of tanks dispersed over many acres. Because your local LP distributor may well be a relatively small franchise holder of a much larger corporation, these businesses are not likely to have yet adopted these systems. When I called my local Amerigas supplier in Mt. Jackson, Virginia, they were vaguely aware of the offerings and and even more vague about their plans.

    SAFETY: "All Centeron propane monitors use a robust Direct Sequence Spread Spectrum battery powered radio for reliable, wireless data communication, even from underground tanks. And each monitor is intrinsically safe, so they can be located in the hazardous area of the propane tank without worry. Installation is quick and easy, requiring no special tools or technical skills. And all have UL50 Type 3 enclosures to provide the protection needed in a propane environment." The reported effective transmission distance exceeds one mile for these transmitters.

    CONFIGURATION: This is an industrial product, designed and configured for industrial applications, but scalable for individual applications. Each offering in this family of products begins with the wireless transmitter and one of several available controllers/receivers. Data from the controllers can be transferred locally to a PC via custom serial port and analyzed with a Robertshaw software offering known as PCView. PCView software is offered at $762 and is probably out of the range of reality for most HS users. Controllers can additionally access the Robertshaw data center through auto dial-up and upload stored data to their hosts that is in turn available a variety of ways including web interface and FTP.

    A POSSIBLE HS USER APPROACH: The remote transmitter costs $129 and includes a long-life battery. The "Residential Controller" that can monitor several tanks, costs $155. Robertshaw charges (I know not how) 50 cents every time a controller uploads data to their center. This is apparently the only charge to use the data center. Given my normal LP usage, the Robertshaw rep advised that a once-weekly upload of stored data would probably be more than sufficient. That's about $25 a year. Although I haven't figured out exactly how to get the data from their center into HS, I am confident that there are several approaches.

    ANOTHER HS APPROACH: The Robertshaw rep offered to make the proprietary serial protocol available for my use if I would sign a non-disclosure. Comm protocols are beyond my technical ability and this really sounds to me like an opportunity for someone more skilled with HS plugins. Additionally, the serial port configuration on the controller is a custom design and would require a Robertshaw configured cable that sells for $123.

    SUMMARY: Given the technical considerations and the additional costs, the second approach is probably out of reach for me. The transmitter costs $129 and the residential controller costs $155. Together this solution would cost $284 plus the dial up charges. In my opinion a robust industrial, but pricey solution. I really want a reliable way to monitor my LP tank, and if the new year brings any joy, I may try this.

    AFTERWORD: Robertshaw once to offered a residential remote LP tank monitor known as the RS-228. This resembled many of the remote thermometers on the market with no data collection and has been withdrawn from the market because of performance issues, largely comm issues that most of us have experienced with the remote thermometers. You can still find references to this on the web.

    AVAILABILITY: The Robertshaw rep provided the retail prices I have quoted here and referred me to the nearest distributor Gardner Marsh, in Raleigh, NC (919-787-8214). Not so near, but an industrial supplier to the gas industry. Haven't called yet. Their web site requires a business account setup to access.

    ADDITIONAL INFORMATION: The Robertshaw web site is a little awkward, but there is plenty of information with pictures and videos, including one detailing the data center offering. Start with this link:

    http://wirelessmonitoring.centeron.net/index.html
    Last edited by deheacock; December 24th, 2009, 10:41 AM. Reason: Spelling

    Leave a comment:


  • Steve Q
    replied
    Originally posted by deheacock View Post
    Steve, you can get a remote ready guage for about $8. Two screws to replace the old one. No you do not have to empty the tank. Link to remote ready guage:

    Purchase:

    http://www.bakersgas.com/rs5909s0273.html

    Data Sheet:

    http://www.maxquip.ca/include/get.ph...=/File/R3D.pdf

    Pictures on the data sheet show the holes for the two screws. Note that they have different shapes around the hole so that the guage only mounts one way. Also, the pics show the Hall Effect connector (black wire) in place.
    Thanks for this info. It turns out that my tank already has a guage that is "remote sensor ready". Even though I've looked at the guage at least 100 times I never noticed the plastic cap that can be removed to add the sensor. My guage says "Taylor Manufacturing" on it. So I will check with my propane company to see what they know about the sensor and if I might be able to get it from them.

    Keep us posted on your progress regarding how you interface the sensor to Homeseer.

    Steve Q

    Leave a comment:


  • deheacock
    replied
    Remote Ready Guage

    Originally posted by Steve Q View Post
    Unfortunately, I have an old tank and it does not have such a guage. I assume the tank would have to be emptied in order to replace the gauge.

    Let us know how well it works when you get it hooked up.

    Steve Q
    Steve, you can get a remote ready guage for about $8. Two screws to replace the old one. No you do not have to empty the tank. Link to remote ready guage:

    Purchase:

    http://www.bakersgas.com/rs5909s0273.html

    Data Sheet:

    http://www.maxquip.ca/include/get.ph...=/File/R3D.pdf

    Pictures on the data sheet show the holes for the two screws. Note that they have different shapes around the hole so that the guage only mounts one way. Also, the pics show the Hall Effect connector (black wire) in place.

    Leave a comment:


  • deheacock
    replied
    A little more info...

    Found this .pdf with a little more info on the PC based system I mentioned before:

    http://wirelessmonitoring.centeron.n...iew%20Data.pdf

    Today must be Robertshaw's Holiday Party - all phones forwarded to recording!

    There is also an interesting video on their site about the data center system they offer to LP companies:

    http://wirelessmonitoring.centeron.net/demo/demo_02.htm

    Relative to other systems I have run-to-ground, it seems Robertshaw really understands their market. Sweet interface, dashboard etc and all the buzz words to make an HS junkie jitter!

    My holiday wishes include:

    I hope the price is reasonable.

    I hope they will sell to individuals.

    I hope the system is as reliable and useful for HS folks as the name Robertshaw is respected in the industry.

    If all of the above works out, I hope my LP supplier will permit me to attach this to the tank, or do so for me for a reasonable fee.

    I'd take a million bucks if none of the above works out for now!

    Leave a comment:


  • Rupp
    replied
    No, this was a perfect place to post more info on how to monitor your nat gas tank. Let us know how you make out.

    Leave a comment:


  • deheacock
    replied
    Robertshaw Propane Monitoring System

    I've been looking for an easy way to monitor my LP tank information thru HS for some time. For what it's worth, came across the following system from Robertshaw:

    http://wirelessmonitoring.centeron.n...ta_pcview.html

    They offer several "solutions" including a central data center solution that they try to sell to the LP companies. But I'm interested in the version of their Centeron Wireless Tank Monitoring System known as PC View, which gets tank information via a wireless transmitter to a base station in your home, that in turn connects to a serial port on your PC, which is running their tank managing software. Apparently you can monitor multiple tanks if you had the need (an agricultural situation) for example.

    If the base station transmits to the PC serial port, I'm guessing that I could monitor that port and intercept the data for use in HS.

    Have no pricing information. Waiting for Robertshaw to return call.

    My LP supplier still delivers with horse and buggy, so I may have to self-install this if I can get it directly from Robertshaw or a third party supplier. BTW, Robertshaw makes most of the "Remote Ready Gauges" now used in the industry that employs hall effect sensors.

    This may not be the proper thread for this information. No offense intended.

    Leave a comment:


  • Steve Q
    replied
    Originally posted by Rico View Post
    My tank already had a "remote ready" guage.
    Unfortunately, I have an old tank and it does not have such a guage. I assume the tank would have to be emptied in order to replace the gauge.

    Let us know how well it works when you get it hooked up.

    Steve Q

    Leave a comment:


  • Michael McSharry
    replied
    Voltage inputs can be read with SECU-16. If memory serves correctly it is a 0 to 10VDC range. I believe the plugin does the scaling so it shows up in Homeseer as a voltage. The outputs are are dry contact relay. You can use it to switch a voltage source.

    Leave a comment:


  • Rico
    replied
    Originally posted by Michael McSharry View Post
    If I was doing it I would use CMAX to control the timing, output the relay to provide voltage and input the voltage. The voltage would be visible to HS where it can be converted to % based upon value change event. If you are not comfortable with CMAX then it could all be done with HS events with recognition that the PC is multitasked so short timing intervals are not very dependable.
    I haven't used the secu16 before. I bought the ocelot and secu several years ago and only us if for IR control. Refresh my memory, can you set one of the inputs to receive analog voltage? Can the reley supply voltage or would it simply be a dry contact switching voltage from an external power supply?

    Leave a comment:


  • Rico
    replied
    Originally posted by Steve Q View Post
    Rico, This looks very interesting. But I'm not clear on what you got for $30? Is it both the gauge and the sensor? Does your tank already have the gauge installed? Where is the circuit board located?

    Steve Q
    My tank already had a "remote ready" guage. I has a little black tab you slide out and slip the $30 hall effect sensor in. It is very tiny, abt 10mmx5mmx30mm. The circuit board is in the sensor and it has three wires connected to it. This thing is designed for a wirless monitor module to clip in here and then connect to a transmitter that sends the data to a reciever in your house which is hooked to phone line and notifies your propane company when the tank needs filling. My company never heard of this sort of thing, but said all the tanks they get now come with the rochester remote ready guage.

    I will have to bury a wire out to the tank, but I already have one to the generator sitting next to it.

    The "hall effect" principal is pretty neat. It is based on a magnetic field that is rotated along with the guage needle.

    Leave a comment:


  • Steve Q
    replied
    Rico, This looks very interesting. But I'm not clear on what you got for $30? Is it both the gauge and the sensor? Does your tank already have the gauge installed? Where is the circuit board located?

    Steve Q

    Leave a comment:


  • Michael McSharry
    replied
    If I was doing it I would use CMAX to control the timing, output the relay to provide voltage and input the voltage. The voltage would be visible to HS where it can be converted to % based upon value change event. If you are not comfortable with CMAX then it could all be done with HS events with recognition that the PC is multitasked so short timing intervals are not very dependable.

    Leave a comment:


  • Rico
    started a topic Propane level monitoring with RD3 hall-effect sensor

    Propane level monitoring with RD3 hall-effect sensor

    I was finally able to aquire a hall-effect sensor for my 500gal propane tank. I found many very expensive $600++ wireless setups, but finally I found the $30 sensor they all use. This was no easy task! I talked to the manufacture, manufacture rep, wireless equipment company, and finally the supplier that they use to get the actually sensor from. The sensor has what is referred to as a "radiometric" output. It has a 5vdc input and the output values are proportional to the tank level percentage. Take a quick look at the pdf:

    http://www.rochestergauges.com/Pages/PDFs/R3D.pdf

    One caution I noticed that you should only apply the +5v for a few seconds, otherwise it will heat up the circuit board and cause errors.

    So what I need to do is:
    Generate a 5v signal only for a few seconds on a preset "tank check" interval. I am thinking every 30min, but this could be a variable that changes. I want to make sure I have some type of resistor or something in place to make sure I don't overload the input current limit of 4.5ma. I then need to have an input read the voltage from the output of the sensor and corrolate that to a percentage. I would like to have this voltage level and percentage show up as two seperate status items in homeseer.

    I have the Ocelot and SECU-16 module.
Working...
X