Black Tank Sensors

[Bora]

I'm looking to install maretron tank sensors on my 2x FW and 1x Diesel tanks, these are all easy to get to to swap out the useless Jeanneau sensors.  Unless someone knows how to calibrate the Schreiber panel?  I already have a Mastervolt monitor which makes the battery readouts from the schrieber erroneous. 

The trickier ones are the black water tanks, to get the forward head tank out i'd have to dismantle the sink area.

I've seen some that work with sticking metal strips down the side of the tank, any experience with these?  I dont' necessarliy need to know exaclty how much is in the tanks but maybe a warning at 75%.

[kapteinkork]

Hi!
i have a SO45DS 2008, i took out the tank sender and measured it, it is standard VDO 3-180ohm , I have ordered a new tank instrument to put in cockpit, I assume the tank readings will be more correct.

kapt. Kork.

[jick]

Hi Bora 

Know this is pulling up an old post - but wanted to ask how you got on with fitting Black Tank Sensors.  I am looking to fit sensors to both tanks - there are none fitted today.  I have looked at the Maretron but they require their tank monitor to program the sensors which makes the costs high

I will also have to drill the tank as there is no fitting for a sensor.  Also trying to find out what kind of fitting i need 

Any suggestions, ideas greatefully received 

Thanks 
John 

[Mistroma]

Jan 17, 2022 22:07:38 GMT jick said:

Hi Bora 

Know this is pulling up an old post - but wanted to ask how you got on with fitting Black Tank Sensors.  I am looking to fit sensors to both tanks - there are none fitted today.  I have looked at the Maretron but they require their tank monitor to program the sensors which makes the costs high

I will also have to drill the tank as there is no fitting for a sensor.  Also trying to find out what kind of fitting i need 

Any suggestions, ideas greatefully received 

Thanks 
John 

I seem to remember that Bora had his boat up for sale and he hasn't visited the site for about 6 months. Perhaps he'd get an email if you sent a message.

I don't know if the 44DS holding tank is similar to translucent variety on the 42DS. I bought a cheap LED patch in a car shop and stuck it onto the rear of my aft. holding tank. I was able to wire it to nearby wiring for a fan. It works very well because the tank is green, translucent plastic and the panel in front is easy to unclip. I just see the level as a dark shadow, nothing unpleasant. It's a very simple arrangement if you have an opening panel and translucent tank. Dirt cheap, highly accurate and no worry about drilling holes.

I believe the 44DS and 42DS holding tanks are in a similar location on the hull just above the bowl. I don't know if the 44DS has a panel with a push button lock.

[jick]

Hi


Thank you for the update on Bora

Yes the 44DS tanks are plastic/translucent (blue/turquoise color) and sit above the bowl in each case.  The panel requires some force to pull off - which I am sure with repeated removal will weaken the clips.  Our current process is to pull the cover off and shine a torch down the tank to pick out the level - so a more basic version of your approach.  The problem is with only 2 of us visiting the boat 2-3 weekends out of 4 in the summer - the tanks are ok for 2-3 weeks so we forget to check !!

I am looking for a solution that either shows up on the MFD (where an alarm could be set) or a big red flashing light.  The light version would be easy to do as a little electronics project - but a boat is probably not the right place.

Hence I like the idea of the external strips Bora and virtualburton have pointed to in other posts.  The ones suggested were SCAD available from Defender.com (if you are in US/Can).  These still have to be connected to the NMEA bus if going for the MFD option.  

[Mistroma]

It sounds as if your tank isn't as easy to see as mine. Another possibility would be to hook up to the Scheiber display as a cheap option. I seem to remember that it has connections for 4 water tanks and 2 fuel tanks. The original unit on my boat would automatically detect additional tanks as soon as a sensor was connected.

DIY circuits shouldn't be too complicated.

1) Water tank connection just expects a voltage between approx. 1-6 volts in steps to give 0,25,75 and 100% readings.
2) Fuel tank connection reads whatever comes back from a 180 Ohm sensor supplied with 3V.

You'd need a circuit to convert capacitive water level sensor (i.e. metal strips) to a variable voltage in the desired range.


Option 2 would give a reading between 0 - 100% when calibrated and the other option would just register the level in steps.

Other external sensor could also be used. You just need a circuit to provide the relevant spare Scheiber unit connections with a variable voltage in the correct range (and some method of tweaking it for calibration).