[MrE]

Wondering if these would work for our holding tanks too.

[hypoxia]

That's interesting!

[kaptain]

I'd guess this probably works great with stationary tanks.
For any tank that moves, unless they have some signal smoothing or stabilization mechanisms built into the unit, the sloshing/stirring of the liquid level in the mobile tank can result in laser detector signal errors, thus, unstable readings.

I searched for user reviews on this laser-based product but didn't find any.
Given the choices available, I would probably go with the ultrasonic-based ones. There are several on Amazon:

1) Ultrasonic Liquid Level (Wireless)
https://m.media-amazon.com/images/I/81INApc3pxS.pdf
https://www.amazon.com/dp/B014MX4BG4/

2) Blue Sea Systems 1810 Tank Sender Vessel Systems Monitor with Diesel, Water and Waste
https://www.amazon.com/dp/B001TS2KPK/
works with only Blue Sea Display VSM 422
https://www.amazon.com/dp/B00GZOCSCI

[MrE]

I'd guess this probably works great with stationary tanks.
For any tank that moves, unless they have some signal smoothing or stabilization mechanisms built into the unit, the sloshing/stirring of the liquid level in the mobile tank can result in laser detector signal errors, thus, unstable readings.

The desired dampening rate is adjusted with dip switches right on the unit to reduce fuel slosh and gauge bounce by adjusting how fast or slow the gauge reacts to the fuel level change.

[Jack Houpe]

I would think it would work on any tank with liquid. My gauge shows full when full and works normal till you get below 1/2 tank then it jumps around which makes me nervous even though I have a piece of Romex to measure depth of diesel in the tank and know how much is in there it still bring me anxiety. I'm going to remove the sender and check the wire wound resistor and if thats not it this laser sender would cure that problem. They make a capacitance sender unit that I've used on planes and cars but don't see how you could put it in the tank without removing it, its straight and rigid.

Thanks for posting Jon.

[Richard]

It’s always a neat concept on how to incorporate newer and better technology into our rigs. I do not want to come across as Debbie Downer, but there a couple of things to consider here and a few additional inputs given my recent replacement of the fuel sender unit.

The newer technology senders require more than one wire to the gauge. Our existing setups are two wire, but one of the wires is ground and is attached to the frame near the sender. The point is that running additional wire from the fuel tank to the cockpit would be required. Then of course, you have to have a gauge that is compatible with the new sender. All of these are achievable, but work and cost involved in pulling this off.

The big issue with the existing sender is it’s antiquated design. The float rides on two thin wires, which change the resistance of the sender as the float moves up and down. They all eventually fail. VDO no longer makes this style sender. Instead they have replaced the sender with technology that has a number of discrete magnetically triggered reed switches. Those switches have different resistance as the float moves up and down the tube.

If you source this sender from VDO you still have the challenge of how to get it into the tank without bending it and rendering it inoperable. I have down this and it’s really a challenge even with removing the door mounting frame. The hole in the tank is ALMOST big enough to pull this off.

There is a company in Florida, KUS that makes a very similar sender except the float is on the outside of the tube, making the tube much smaller in diameter. Small enough to make the almost hole large enough to permit replacement with the tank in place.  https://kus-usa.com/product/sss-ssl-send...W8QAvD_BwE    This is just a pic to illustrate the sender. If you decide to go this way, you will need to specify to KUS both the length and resistance required. This is going to be unique to each fuel tank  AND the gauge style Newell chose.

Again, I am not trying to discourage anyone from adopting the new technology, just making you aware of alternate tech to solving the problem of inaccurate fuel readings.

[MrE]

The newer technology senders require more than one wire to the gauge. Our existing setups are two wire, but one of the wires is ground and is attached to the frame near the sender. The point is that running additional wire from the fuel tank to the cockpit would be required. Then of course, you have to have a gauge that is compatible with the new sender. All of these are achievable, but work and cost involved in pulling this off.

The only extra wire required is a switched +12v power that doesn't need to come from the cockpit. The following is from 19-250.pdf

Sender Wiring

1) Connect a good ground to the stud on the sender labeled
“GND”.
2) Connect a switched +12V power to the stud on the sender
labeled “+12V”.
3) Connect the fuel gauge’s signal wire/stud to the stud on the
sender labeled “Gauge”.

Sender / Gauge Calibration

Averaging Switch Settings
ON - ON: Minimum averaging with fastest response. (Helpful when bench testing)
ON - OFF: Short averaging.
OFF - ON: Medium averaging.
OFF - OFF: Long / normal averaging with longest response.
The correct averaging setting depends on the fuel tank size and volume. Normally, using a long average setting will
make readings smooth, but may update slowly when fuel level changes. In reality, fuel level change is very slow, so the long / normal averaging setting is recommended.
Calibration Steps
You don’t have to calibrate all settings. Each calibration setting can be set independently. For example, if you change to
a new gauge, you only need to calibrate the gauge settings, the tank low and full settings are still good. You can also calibrate
the gauge without the fuel tank and calibrate the fuel level without the gauge.
Press and hold P1 until the slow flashing green status LED turns off, then release the button to enter the calibration
mode.
Standard Gauge Calibration (short sweep)
1) Gauge Empty Position:
a. The LED should be solid blue. Press P2 or P3 to move the gauge pointer to empty. If the pointer is initially
above full or below empty, you may need to keep holding P2 or P3 for up to 8 seconds before you see the
pointer move.
b. When the pointer is positioned to empty, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
2) Gauge ½ Position:
a. The LED should be solid green. Press P2 or P3 to move the gauge pointer to ½. If the pointer is initially
above or full or below empty, you may need to keep holding P2 or P3 for up to 8 seconds before you see the
pointer move.
b. When the pointer is positioned to 1/2, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
3) Gauge Full Position:
a. The LED should be solid red. Press P2 or P3 to move the gauge pointer to full. If the pointer is initially
above or full or below empty, you may need to keep holding P2 or P3 for up to 8 seconds before you see the
pointer move.
b. When the pointer is positioned to full, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
P1 P2 P3 GND +12V Gauge
Averaging Setting Switches
Status LED Calibration Buttons
Classic Instruments Full Sweep & Programmable Fuel Gauge Calibration
Set the fuel gauge to operate with a standard universal (240-33Ω) sending unit. Make sure the gauge is powered and
connected to the fuel sender.
1a) Gauge Empty Position:
a. The LED should be solid blue. Connect a DC voltmeter to read the voltage on the “gauge” post of the
sender. Press P2 or P3 to adjust the voltage to 2.69V.
b. When you have the required voltage, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
2a) Gauge ½ Position:
a. The LED should be solid green. Connect a DC voltmeter to read the voltage on the “gauge” post of the
sender. Press P2 or P3 to adjust the voltage to 1.66V.
b. When you have the required voltage, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
3a) Gauge Full Position:
a. The LED should be solid red. Connect a DC voltmeter to read the voltage on the “gauge” post of the sender.
Press P2 or P3 to adjust the voltage to 0.63V.
b. When you have the required voltage, press and hold P1 until the LED turns off. Then, release the button.
The LED will flash red 3 times to confirm the new setting is saved. If the LED doesn’t flash red 3 times, the
new setting is NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be saved, and you will skip to the next setting.
Tank Calibration
4) Tank Empty Position:
a. This calibration is to set the tank empty (away from sender) level.
The LED should be flashing green.
b. Set up a flat target and sensor parallel to each other on a table.
Set the distance between them equal to the depth of your tank
minus a small reserve distance (1/2” reserve is typical). The LED
will flash faster the closer the target is to the sender.
c. Once the correct distance is set, wait at least 10 seconds to make
sure the sender’s reading is stable.
d. Press and hold P1 until the LED turns off. Then, release the
button. The LED will flash red 3 times to confirm the new setting is
saved. If the LED doesn’t flash red 3 times, the new setting is
NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be
saved, and you will skip to the next setting.
5) Tank Full Position:
a. This calibration is to set the tank full (near sender) level. The LED
should be flashing blue.
b. Set up a flat target and sensor parallel to each other on a table.
Set the distance between them equal to the distance between the
bottom of the sender and the full fuel level + ¼”. The LED will
flash faster the closer the target is to the sender.
c. Once the correct distance is set, wait at least 10 seconds to make
sure the sender’s reading is stable.
d. Press and hold P1 until the LED turns off. Then release the
button. The LED will flash red 3 times to confirm the new setting is
saved. If the LED doesn’t flash red 3 times, the new setting is
NOT saved.
NOTE: If you only momentarily press P1, the current setting won’t be
saved, and you will exit the calibration. The status LED will return to a slow green flash.

[Richard]

Thanks Jon for the additional info. The more solutions we have for outdated technology the better.

[kaptain]

I'd guess this probably works great with stationary tanks.
For any tank that moves, unless they have some signal smoothing or stabilization mechanisms built into the unit, the sloshing/stirring of the liquid level in the mobile tank can result in laser detector signal errors, thus, unstable readings.

The desired dampening rate is adjusted with dip switches right on the unit to reduce fuel slosh and gauge bounce by adjusting how fast or slow the gauge reacts to the fuel level change.

Have you tried it yourself on a mobile tank? If so, please share some of your personal experiences.
I am thinking of giving it a try on my 1989 CAT 963 loader, which doesn't have a fuel gauge.  But I am concerned that I have to buy a third party display as it doesn't come one, and after drilling holes then finding out the reading is too jumpy to be readable.

[MrE]

Have you tried it yourself on a mobile tank? If so, please share some of your personal experiences.
I am thinking of giving it a try on my 1989 CAT 963 loader, which doesn't have a fuel gauge.  But I am concerned after drilling a hole in the tank and then finding out the reading is too jumpy to be readable.

I have not tried it myself. I am thinking about trying a couple of them on my holding tanks which I have no gauges for as well as my fuel tank. Pretty sure this would be a more elegant solution for the black tank than a sending unit with a float.