Propane level monitoring with RD3 hall-effect sensor

Monitoring Propane Tanks via Web based controller

Does anyone have any updates to monitoring propane tanks?

I was going to use an X320 Controlbyweb device to monitor the Rochester Hall effect dial. However getting a hold of the Hall-Effect module is very difficult. The dial is easy to obtain, but it seems Rochester Gauges has a relationship with Robert Shaw and keeps hose modules in tight control. Crazy business model in my eyes...

Where can you obtain the hall-effect module and which one did you use?
Rochester makes them, but I also believe Taylor manufactures them also.

I have a similar setup, a 500 gal propane tank with a CatV wire run underground and am looking to monitor the tank levels without paying through some continuing service model based systems like Centeron.

Thanks, Rob

Monitoring Propane Tank Levels via PC

I stumbled upon this thread... Perhaps a solution I came up with can help some of you.

My underground 500g propane tank had a sensor ready gauge on it.
I installed a R3D Hall Effect module (sensor) on the gauge.
I had buried a 1.5" plastic conduit from the tank into my home anticipating remote monitoring and not trusting wireless technology for it.
Tank is 125' from the house.
I ran normal Cat-5 in the conduit - connecting the three leads of the Hall Effect module - use two pairs to deal with common mode rejection and insure a stable signal 125' away.
Inside the house I have a "monitoring" PC that captures data from a bunch of temperature sensors, wind and solar power sensors.
There is also a USB analog/digital I/O device on this PC keeping track of various things.
Wrote a simple C++ program that sends +5V to the tank sensor for a few seconds via a digital output - while reading the output voltage of the sensor on an analog input. Using the voltage to level table provided by the R3D, I get a very accurate and very reliable reading of the tank level into my PC. Has never failed - is completely immune to weather.

Results are here for me (or anyone) to see from anywhere at anytime: http://NovaBarnTemps.selfip.com updated every minute.
Same program will send me eMail when anything needs attention - including the need for a tank refill (triggered at 30% full).

I'm sure HomeSeer could use that same technology...

Good luck - have fun!
Gene

[RBergquist]

Implemented RobertShaw Propane Monitor script

After coming up to our house twice this winter to find the Propane had run out. (The Propane company Degree Days routine doesn't work well with intermittent house usage), I went ahead and got the setup mentioned in the post above (http://forums.homeseer.com/showpost.php?p=901785&postcount=13)

It is working fine and I called our Propane company and set up an arrangement for me to email their Operations desk when the level gets low. They were quite happy to work with me and really wanted to avoid Propane Out situations.

I had to sign an NDA with RobertShaw so I can't post the code, but would share it with anyone that shows me their NDA.

[Mark42]

"but I would be very careful about any type of switch or relay in the vicinity of the tank, especially under the cap. Note that the Robertshaw transmitter is rated "intrinsically" safe whatever that means."

http://www.engineeringtoolbox.com/ha...ion-d_345.html

The electrical classification of a propane tank would probably be Class 1 Div 2 which indicates that hydrocarbon vapor could be present in abnormal situations e.g. a leak during filling.

In this classification, intrinsically safe equipment is required.

http://en.wikipedia.org/wiki/Intrinsic_safety

Safety of design cannot be stressed enough when it comes to dealing with hydrocarbons, especially when vapor can exist.

I ran across this use of load cells for a large propane tank (I have been considering a similar problem for a 275 gallon heating oil tank in the basement)

http://www.propanecouncil.org/uploadedFiles/11722.pdf

While they were not happy with the cost effectiveness of their result, the concept of using a load cell is appealing. For a fill/no fill decision I would think a single load cell would be sufficient. Mounting such a device in an as-built situation may be an issue however.

Mark

[deheacock]

Heating Degree Days

That might work, but I would be very careful about any type of switch or relay in the vicinity of the tank, especially under the cap. Note that the Robertshaw transmitter is rated "intrinsically" safe whatever that means.

Another way to "calculate" current usage is to track heating degree days with historic usage. That's how my LP company schedules deliveries and I think most do it this way.

It's crude but accurate enough for their purposes. You can get degree day info for your geographic area and a world of other information at this site:

http://www.degreedays.net/

Beyond its crudeness, the only real problem is if Grandma comes to visit, stays three weeks and cranks up the thermostat to 80 while she is there. Since that affects usage and the LP company has no way of knowing about her visit, they can sometimes be way off.

If you are tracking temps or thermostats with HS you can compensate for these events in your calculations I would think. But you still just have an approximation and whether or not this gives you more accurate estimates than your current method, I wouldn't know.

So....SAFELY reading that dial on the tank is still my goal.

[Steve Q]

Excellent job researching this; thanks! I agree that $200 is too pricey. But I am still interested in some kind of monitor for the tank. I don't think it has to be very accurate. For my purpose I just need to know when the tank is less than 25%. I am just looking for a way to get Homeseer to send me an email/voice reminder saying "the propane level is low, please schedule a tank refill". I currently track my propane usage by measuring my furnace ON time. (See thread: http://board.homeseer.com/showthread...552#post865552).
So I have a pretty good way to track my propane usage. I guess I could create a Homeseer event that could start a counter when my 500 gal tank is filled and then add the number of gallons used each day. When the total gets to 400, it could trigger a "Refill Propane Tank" event. It would be nice if there was a way to automatically detect when the tank was filled!

After thinking about this a bit, I think I will try using a DS10A door/window sensor attached to the tank lid. The logic would be:

• if the tank lid is open for 10 minutes (about how long it takes to fill the tank)
• and if the number of gallons used is greater than 350
• and if it is wintertime (date between 10/1/Y and 4/1/Y)
• then reset counter to 0

I think this might work!

What do you think?

Steve Q

[deheacock]

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

[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.

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

[deheacock]

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

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.

[deheacock]

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!

[Rupp]

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.

[deheacock]

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.

[Steve Q]

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

[Michael McSharry]

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.

[Rico]

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?