Guide

Welcome

Gobius C is an entirely new tank monitoring system that gives you the exact level and volume, regardless of the tank’s geometry. It was developed for those who want to know the exact tank level so there is no guessing, no in-tank installation, and no in-tank mess. It is simple and precise so you can ’C’ inside your tank accurately.

Security warning

Tank monitor systems should only be installed by a person competent and experienced in working with electrical systems and fuel tanks. All work involving fuel tanks should be performed with extreme care due to the possibility of igniting fuel fumes. Our tank monitor systems are designed to be accurate and reliable. However, they should be used only as aids.

When you download the app, you need to be connected to the Internet, but after that, you don’t need to be connected to the Internet. If you want to see the tank level on your smartphone, you reach the sensor via your phone’s Bluetooth. Finally, your phone isn’t needed if you’re connecting the sensor to a control system or gauge.

This information is in three parts

  • In the box
  • Mounting the sensor on the tank
  • Setup the sensor

In the box

Gobius C is ready to use; everything is in the package. You have the sensor with a pre-mounted 3M tape, a quick guide, and an extra 3M tape. If you have acquired a Gobius C (black) for NMEA 2000, it comes with a cable that you can use to connect the sensor directly to the NMEA 2000 network. Suppose you have purchased a Gobius C (orange) with analog outputs. In that case, it comes with a cable to connect to a power source (12-24 V) and to connect external devices, such as warning lights/buzzers, control systems, and analog instruments. The quick guide gives you a brief overview of the installation. The sensor is waterproof, IP 66.

Mounting the sensor on the tank

Explain how you attach the sensor to the tank and the difference between plastic and metal tanks. For metal tanks, you need a hole in the tank wall. Gobius C can’t read through metals like stainless steel, steel, and aluminum. For all kinds of tanks, you need at least 65 mm of space above the tank.


Setup the sensor

This section explains how to attach the sensor to the tank and the difference between plastic and metal tanks. You need a hole in the tank wall (1 ¼”) and our adapter for metal tanks. Gobius C cannot read through metals such as stainless steel, steel, and aluminum. For all types of tanks, you need at least 65 mm of space above the tank.

Let’s start!

Sensor for NMEA 2000

Sensor with analog outputs

Guide 1

Installation on plastic tanks

Please note that this Gobius is mounted on the top of the tank, not on a vertical side. Remember that this top wall must be horizontal, i.e., not inclined.
Maximum tank wall thickness is for polyethylene 12 mm, fiberglass 8 mm, and glass 5 mm.

  1. Find a place not too close to an edge; the minimum distance is 35 mm from the sensor’s edge to the tank’s edge.
  2. Clean the surface of the tank with the 3M tissue. You can also use Acetone.
  3. Check that the temperature on the tank is at least 20C / 76 F.
  4. Place the sensor on the tank and press it hard.
  5. Wait 15 minutes for the tape to harden.

Note:
You need at least 65 mm of free space above the tank for mounting the sensor.
This is also important. Nothing inside the tank must make it not a “clear view” for the sensor to measure the fluid level all the way down to the bottom.
If you want, you can put a silicone string around the edge of the sensor to strengthen the attachment. We do not recommend using two-component glue to attach the sensor.

Guide 2

Installation on metal tanks

You must have a hole in the tank wall at least 44 mm in diameter for all kinds of metal tanks. Gobius C can’t measure through metal walls. Many tanks have “standard” holes for internal level indicators, like Wema and compatible level indicators (KUS, VDO, Biltema…).

Standard hole, 1 1/4″
You must unscrew the other level indicator to mount our sensor, but keep the bracket in the tank.
With our Adapter (ordered separately), you can use the bracket on the tank and mount the sensor. If you have long screws in the bracket, you should change to short ones. Long screws can interfere with the measurement.

  1. Find a place not too close to an edge; the minimum distance is 35 mm from the edge of the sensor to the edges of the tank
  2. Replace the screws in the bracket
  3. Remove the protective paper from the tape
  4. Put the sensor on the adapter and screw it down by hand; not too tight
  5. Wait 15 minutes for the tape on the adapter to harden

Note:
You need at least 90 mm of free space above the tank for mounting the sensor. This free space includes the adapter.
This is also important. Nothing inside the tank must make it not a “clear view” for the sensor to measure the fluid level all the way down to the bottom.

Guide 3

Connect to a power source, 12-24 Volts

Later in this instruction, you will see how you set up the sensor precisely for your need. Use the black wire to  – connector and the red to +. (If you do the opposite, no damage occurs.) The red lamp on the top of the sensor will light solid when it’s connected to power. Later on, the lamp will flash when the sensor is measuring.

 

Analog cable
NMEA 2000 cable

Guide 4

Integrate with control systems and external devices

With Gobius C, you can integrate the sensor with other systems. In addition to seeing the exact level on your phone, you can see the current status of external instruments and your control system. The table and the illustration show all possibilities.

text Alt Text

Analog outputs, wiring diagram

Red Black White Grey Brown Green Yellow Blue

Power (12-24 V) +

X

Power (12-24 V) –

X

Output 0-5 V

X X

Current loop, 4-20 mA –

X

Current loop, 4-20 mA +

X

Alarm 1

X X

Alarm 2

X X

Resistive out, 10-180 / 240-33 Ohm

X X X

Download here a detailed description of all outputs.

Guide 5

Setup the sensor

Now the last part remains to start using your new tank sensor. You must now specify which liquid, tank geometry, tank depth, volume, etc., apply to your tank. You can also specify which alarm levels (in %) should be used, as well as if you intend to connect the sensor to an external gauge or control system, i.e., which signal the sensor should be set to (10-180/240-33 Ohm, 4-20 mA or 0-5 Volts.

Please download the app from App Store or Google Play

Note:
The automatic calibration is done for the sensor to learn the characteristics of your tank. This is needed during a new installation but also at other times. Your app always reminds you when needed.

Very important for the Calibration
The calibration aims to measure radar reflections from static objects near the Gobius C sensor. During the calibration, the distance from the top of the tank to the liquid level in the tank must therefore be greater than 150 mm (6 in).

Never overfill your tank
Overfilling your tank for all liquids, especially petrol, and diesel, is never good. Therefore, be careful when you see on your phone or on an analog instrument that the tank is about to be 100% full. In Gobius’ world, 100% full is 60 mm from the top of the tank. This is to help you not overfill your tank, i.e., you get a safety margin you should not exceed.

 

Useful information about the app

Fluid Type

You can choose from most fluids, such as freshwater, gray water, black water, diesel, petrol, and oil. If you change the setting from water to fuel, you should do a new calibration.

Voltage

Minimum 9 Volt and maximum 28 Volt.

Tank Geometry

Tanks have different forms. Our Tank Calculator helps you calculate the tank’s volume and the correct level.

Distance for tank Empty

This refers to the tank’s depth, which can be a maximum of 2 meters (78.7 inches) and a minimum of 200 mm (7 7/8 inches). If the tank has a sloping bottom, you should always place the sensor directly above the tank’s maximum depth. The sensor must not be placed too close to a vertical edge; the minimum is 35 mm (1 3/8″).
There must always be a clear line of sight from the sensor down to the bottom of the tank.

Note:
This is the distance from the sensor’s underside to the tank bottom OR to the fluid level where a 0% indication is desired. If the fluid is oil-based (Diesel, petrol, gasoline, etc.), it is crucial to set this distance about 30 mm LESS than the actual distance from the sensor to the tank bottom; otherwise, the sensor may erroneously report that the tank is empty even though there is some fluid in the bottom.

Tank Adapter

The sensor does not measure through metal (steel, stainless, or aluminum) tanks. But if there is an existing hole, for, e.g., Wema’s internal gauge, with a thread, SAE 5, 2 1/4″, you can use our Adapter, which is screwed into the flange. Then, you mount our sensor on top. You need approx. 100 mm on top of the tank to accommodate the sensor and adapter.

Installation Location

If you want a quick measurement, select On land. On sea, it measures a little slower but compensates for the boat’s movement when there are large waves. Both choices work on land and sea.

Bluetooth off or On

You can turn off Bluetooth so no one else can communicate with your sensor. You can always turn Bluetooth back on but within 10 seconds after you have powered the sensor on again.

Outputs Settings

These selections only apply to Gobius C, orange, and gray color sensors. Black sensors can only be used in an NMEA 2000 network.

Alarm level 1 and 2

You can choose to have two alarm levels, for example, to control an audible alarm or other external device. You may want to alarm when the tank is about to be empty or before it is about to be full. The bar graph shows these alarm limits on your phone as red lines.

Output

Active Low (NPN) or Active High (PNP)
The setting shall be selected depending on the electrical load connected to the alarm output: If the load is connected between the output and electrical ground (power supply negative lead), select Active High (PNP). If the load is connected between the output and the power supply positive lead, select Active Low (NPN).

Advanced Settings

Distance for Tank Full (mm)
This is the distance from the underside of the sensor to the fluid level, where the sensor shall indicate that the tank is full (100%). This value is 75 mm at minimum and can be increased if the sensor is located a considerable distance above the maximum fluid level of the tank to make it possible to get a 100% reading.

Length of adapter (mm)
This is the length in mm from the underside of the sensor to the inside of the tank roof when using an adapter for metal tanks. The value is 20 mm when using our tank adapter but can be increased if a custom-made adapter is used. The sensor compensates for this distance when measuring.

Averaging filter constant

This constant controls a sensor smoothing filter. Smoothing may be used when the sensor is installed on a boat, as the boat’s movement may result in uneven level measurement. A value of 0 disables smoothing. A value of 3 is the default for “On sea” sensor installation. A higher value gives smoother results but slows the sensor’s reaction to changes in fluid level (for example, when filling the tank).

Threshold Multiplier Near Range
Threshold Multiplier Mid Range
Threshold Multiplier Far Range
“These parameters may be used to increase the threshold for the radar sensor with respect to detection of the fluid surface. The typical usage is if the radar sensor erroneously interprets radar reflections from structures in the tank or from irregularities in the tank wall as fluid ( For example, if the sensor is located near an irregular wall). The location of such irregularities can be found using the ” Sensor Details ” button. If the tank is empty, the sensor will show the distance where the irregularity is found in mm. The sensor also shows which ” range ” is used as follows:
Range 1 is Near Range with a distance of 0 to 125 mm from the sensor
Range 2 is Mid Range with a distance of 70 to 900 mm from the sensor
Range 3 is Far Range with a distance of 750 to 2000 mm from the sensor
The default value of the multipliers is 1.0. It is recommended to increase the multiplier in steps of 0.5 (to 1.5, 2.0, etc) for the range where the problem is located.”

Factory reset

The easiest way to return to the basic settings is to delete the sensor in the app and then redo the installation in the app.

Sensor Details

New text will come soon.

Remove

Deletes the sensor in your app.

Calibrate

coming soon

Save

When you have done a new installation or a change, you must always save so that the app and the sensor can remember the settings.

Sensor location

To detect that the tank is empty, the sensor must be installed above a portion of the tank where the bottom is horizontally flat. There may not be any physical objects (such as tubes) in the tank between the sensor and the tank bottom.