Electric Vacuum Sensor/Gauge

vas said:
for the record,

Normal stock Engine Dynamic Parameters PGN127489 does have a engine fuel pressure parameter. However, this wont accept negative values, I guess is there in order to measure pressure on the fuel pump, so not suitable.

PGN130314 is an odd one, Timo only lists PressureSources for Atmospheric, Water, Steam, CompressedAir and Hydraulic (4). Will search and see if indeed 5 Filterpressure is accepted and see where I can show it (well, not much point doing something if nothing supports its display...)

Alternative is to use PGN127489, and issue a engine warning if value drops lower than something I set. Means I don't actually broadcast the pressure value (would be wrong as I'd have to drop the minus...) just a warning/error message that will be broadcast on all NMEA2K devices (GPSMAP plotters, 4in displays, Maretron, etc). I'm using this feature already for some events, works fine.

Will also check the custom PGNs that Maretron FPM100 broadcasts and see if they are suitable,
will report when back on the boat next week

cheers

V.
Click to expand...

talking blx, had v.old libs, updated (after asking the developer)
So fact is that PGN130314 will work fine to inform the NMEA2000 bus on filter pressure/vacuum a value supported by Garmin Maretron (and I guess others) will test it with a dummy negative value to establish all's fine and then work on it.
Now main issue is getting a decent robust sender that has proper threaded body to bolt onto the Separ alloy cap and will report in 4-20mA most likely.
Thread no issue as cap is not threaded, I'll have to drill and tap!
Main issue is finding a sender that does vacuum, almost all seem to be doing pressure only :-(
any pointers welcomed!

cheers

V.
 
nice and cheap (most likely) options guys, you are aware it's going to be a pig to calibrate these things, right?
a 4-20mA is going to be an easy job, not to mention will look good on top of the separs compared to a washing machine part :-p
Hope I'll find two!

V.
 
vas said:
nice and cheap (most likely) options guys, you are aware it's going to be a pig to calibrate these things, right?
a 4-20mA is going to be an easy job, not to mention will look good on top of the separs compared to a washing machine part :p
Hope I'll find two!

V.
Click to expand...

Calibrate with either a vacuum gauge or a manometer. A water manometer could be used if you can get the height.

35 kpa = 140 inches of water.

The set points come from one of these.

rac-rk19668_3.jpg
 
vas said:
nice and cheap (most likely) options guys, you are aware it's going to be a pig to calibrate these things, right?
a 4-20mA is going to be an easy job, not to mention will look good on top of the separs compared to a washing machine part :p
Hope I'll find two!

V.
Click to expand...
The map sensor I used for something else entirely was well specified as xmV per psi or whatever, linear output in the range 0 to 5V.
Read the volts with the machine switched off to get zero, although that doesn't change from day to day.
Hardly worth warming up an Arduino for, except they're cheaper than a pot, an op amp and a DVM these days.
 
TernVI said:
The map sensor I used for something else entirely was well specified as xmV per psi or whatever, linear output in the range 0 to 5V.
Read the volts with the machine switched off to get zero, although that doesn't change from day to day.
Hardly worth warming up an Arduino for, except they're cheaper than a pot, an op amp and a DVM these days.
Click to expand...
I'll look at it, although I'd rather have something with proper threads I can bolt onto the lid of the prefilters.
TBH not too keen on having circlips and hoses in something as vital as fuel supply to engines!
Getting air in the diesel lines is not my idea of sensing and collecting data.
BTW, I have found a couple of options that are meant to measure air vacuum, and one that does fuels/oils. Thing is the oils one is 50quid, the others are much cheaper at 20euro a piece. I'm talking ebay obvs!

Arduinos (well 1 due and 5 teensies) are already there doing all sorts of things, adding two 0-5V or 4-20mA inputs to them is really nothing.
When winter kicks in, I'll write a lengthy report on my N2K works!

cheers

V
 
vas said:
I'll look at it, although I'd rather have something with proper threads I can bolt onto the lid of the prefilters.
TBH not too keen on having circlips and hoses in something as vital as fuel supply to engines!
Getting air in the diesel lines is not my idea of sensing and collecting data.
....
Click to expand...
I don't disagree with that!
Least invasive way would be looking at the current drawn by an electric fuel pump perhaps?
 
TernVI said:
I don't disagree with that!
Least invasive way would be looking at the current drawn by an electric fuel pump perhaps?
Click to expand...

nice out of the box thinking, but both main engines have manual lift pumps Bosch (I think) so not an option.
Seems that I found a packet of 3 senders -1bar to 2bar for 40USD shipped, s/h obvs. I think I'll give it a go (may even put the third one on the yanmar genny engine :-)

V.
 
vas said:
nice out of the box thinking, but both main engines have manual lift pumps Bosch (I think) so not an option.
Seems that I found a packet of 3 senders -1bar to 2bar for 40USD shipped, s/h obvs. I think I'll give it a go (may even put the third one on the yanmar genny engine :)

V.
Click to expand...
got one of these (well, actually 3senders) they are 0.5-5V output -1 to 2bar s/h and for 50USD delivered. Seller has more if anyone is interested!
Vacuum Pressure Transducer Sensor -14.5-30 PSI Oil Fuel Gas Air Water 3-pcs | eBay

seems that you can get them new at 18USD a piece, and of course they come from CN (and cannot be delivered to Europe from where I found them in ebay).
Vacuum Pressure Transducer Sensor -14.5-30 PSI Oil Fuel Gas Air Water Stainless | eBay

brand is NOPTEG and model is AC-JXL-054. Not much info on them!

cheaper than two decent ss vacuum gauges from WIKA that i'd be able to see only in the e/r, so definitely better option for me.

cheers

V.
 
me again,
for anyone following this, turns out that the main problem is not getting a reasonably priced sender, but presenting filter vacuum on a NMEA2000 display!
Neither my GPSMAP4K and 5K plotters and GMI10s, nor a Maretron display will do it via PGN130314. They both do fuel pressure (through PGN127489 positive and obviously from the engine fuel rail or anyway after at least the liftpump) which is no good at all, unless I get into hacks with dropping the negative values and presenting them there for monitoring purposes. I'll search a bit more and come back with a better solution (if there is one that is!)

cheers

V.
 
vas said:
me again,
for anyone following this, turns out that the main problem is not getting a reasonably priced sender, but presenting filter vacuum on a NMEA2000 display!
Neither my GPSMAP4K and 5K plotters and GMI10s, nor a Maretron display will do it via PGN130314. They both do fuel pressure (through PGN127489 positive and obviously from the engine fuel rail or anyway after at least the liftpump) which is no good at all, unless I get into hacks with dropping the negative values and presenting them there for monitoring purposes. I'll search a bit more and come back with a better solution (if there is one that is!)

cheers

V.
Click to expand...
You could try this company , Oceanic Systems (UK) Ltd | World Class Systems for World Class Yachts I found them very good to deal with .
Have they threaded pressure sensors inc vacuum General Purpose 4-20mA Pressure Sensors | Oceanic Systems (UK) Ltd
and an adapter to convert to n2k Pressure Adaptor 4-20MA | Oceanic Systems (UK) Ltd | World Class
It does use PGN 130314 but they might have an answer to displaying it
 
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