Black Tank Sensor

[Blackcloud]

I also had the screen lock up on me. After I finally got a read on the screen it looked like it was going to work. 5% then 10% then topped out at 20%. It should have been reading 50-60%. Can’t trust it when dry camping. When my read only zero, per a service tech in Atlanta, I disconnected coach power for a few seconds. It came back up to a read but never in proper calculations.

 

[NWIP]

Have you tried this procedure to recalibrate. You need to have a flow meter to know how much water you put into the back tank prior to setting full level

 

[redbaron]

@Blackcloud I think the first recalibration you did messed up. The original problem was a typical kib freeze on communication. The power reset is the correct action.

Once you have done a reset, then do the full recalibration again. That should fix it.

Fwiw, the pressure sensor seems to be working, or dead. The dead ones are usually revived with power reset.

The working ones, once calibrated, are very accurate.

 

[DavidL]

The problem with ARD's picture is the pressure sensor is not oriented correctly. It needs to be level with the bottom of the tank. It is measuring the water column pressure. Pointed the way it is, it won't measure the last 20% of the tank and all measurements would need to be calibrated less the 20%. The problem with water pressure sensors is the port / sensor getting plugged and not sensing pressure anymore. Rotate it 90 more degrees and recalibrate.

A better design would be a fitting to allow air to be pushed to clear the "crap" in the port...but without ruining the sensor that has to be pretty sensitive. 2.31 feet of water / per PSI. So looks like their sensor is rated up to 3psi so can support a tank that is 7 ft tall. I think that'll do it....
Nothing new with this design...but new apparently to RVs.

 

[redbaron]

The sensor is in the pipe attached to the bottom of the tank. The pipe will fill first before the tank holds water, since gravity dictates water will always flow downwards.

The orientation of the sensor does not matter, as that pipe will be the first to fill.

As the tank above collects more volume, this sensor will detect it.

I have personally experienced this sensor design in both black and gray, and can report that it is very accurate all the way from 0 to 100.

 

[Dona40]

Agree with Redbaron. That's what "calibration" is for.

 

[Dona40]

As long as the sensor is at or below the bottom of the tank, you would need real high-tech equipment to tell the difference, and do we have to worry about 1 pint or so at the beginning of the fill?

 

[DavidL]

No "high tech" equipment required. In reality, just a voltmeter and a conversion chart...
The pressure sensor needs to be fairly sensitive as the pressures are pretty low.

Another type is a pressure sensor that is on a wire and is submerged...I use these for Wakeboard boat ballast tank level sensing (lake water, no solids). Industry uses these for sludge tank monitoring.

But the issue of blockage remains. If the pressure sensor was on a T and the other side of the T went Up and over the top of the tank vented to air, then you could push air down that tube to clean...but the pressure sensor has to be rated to not get damaged with the increase in pressure. And the sensor needs to be at the bottom (or lower) of the tank to near fully show 0 - 10% full.

 

[FrankE]

Can I just say Hallelujah! Newmar is done with KIB. As many of you know, I, as many others, have had issues with my black tank sensors reading properly from year 1. I've had new sensors, water pump relocated, new board, software updates, tons of recalibrations to no avail. This past visit to Newmar has taken care of my problem. Newmar unplugged the KIB pad on the tank and installed a a sensor by the gate valve that works by pressure (gravity). The higher the water level, the more pressure you have. It is working so far. No red lights, no showing 100% full when empty. It's the little things! Oh and the floater is still in the tank, so IF you do get a full tank reading when you think it's not full, you can pull the famous yellow wire and if it is still red, you know you are full. ?

thank you for posting this cause we have the red light and can’t flush either toilets. Hopefully we can get this red light turned off so we can flush and then have your fix done. Thank you again

 

[Buly]

There is a way to measure the increasing pressure in the tank, without the sensor being in contact with the sludge. ( I want royalties for that ).
Imagine a tube with the sensor at one end and open at the other. Submerge it with the open end down. The increasing fluid level in the tank will create increasing pressure in the air pocket, without reaching the sensor. All you have to do is calibrate it