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Author Topic:   Lowrance EP-60R Re-calibration
Sfef84 posted 05-30-2012 12:04 PM ET (US)   Profile for Sfef84   Send Email to Sfef84  
The standard method for recalibrating fuel flow sensors is:

1)Go into fuel flow settings on display and press "re-calibrate"

2) Connect the meter to a external gas tank with 5 gallons (or known amount of fuel)

3) Run the boat until the tank is empty.

4) Tell the display how much fuel was used

I want to propose a new method:

1) Remove fuel flow sensor from primary gas line (but leave it connected to NMEA network)

2) Re-install fuel flow sensor into a spare fuel hose.

3) With a funnel on the top and a empty 5 gallon gas tank on the bottom, Pour 5 gallons of gas down the hose at a steady pace.

4) Tell the display how much fuel has passed through the sensor

I think this is a faster, cheaper, more controllable re-calibration.

Any thoughts?

newt posted 05-30-2012 01:10 PM ET (US)     Profile for newt  Send Email to newt     
It sounds good except that the sensors are supposed to be oriented up so that the fuel flows from the bottom to the top of the sensor. You would need to use a fuel tank elevated above the sensor, loop a fuel line below the sensor and another fuel line from the top of the sensor into the bucket or second tank.
Sfef84 posted 05-30-2012 01:21 PM ET (US)     Profile for Sfef84  Send Email to Sfef84     
Details... details... jk.

I think that the sensor pointing down would still work with my method. Correct me if I'm wrong but the purpose of the sensor oriented vertically is to prevent "re-counting" (i.e. the fuel must be pulled up the sensor via the fuel pump. If sensor is oriented horizontally, the fuel can slush back and forth through the paddle wheel in the sensor)

jimh posted 05-30-2012 06:27 PM ET (US)     Profile for jimh  Send Email to jimh     
I will tip my hat to the ingenuity of the proposed method. It provides a means for running many gallons of fuel through the sensor while knowing the actual volume with precision. I could see using this method in a repeated fashion to run perhaps 50-gallons of fuel through the sensor. The more gallons used in the calibration, the more the error magnitude of the sensor calibration. That ought to make it easier to correct.

As a corollary to the method, perhaps we could dispense with using gasoline entirely in the process. Use water as the liquid to be passed through the sensor. You could just let the water flow overboard after passing through the sensor. This would be simpler than handling the gasoline fuel.

The concern might be that the flow sensor could be slightly off its calibration if the fluid were different density.

Sfef84 posted 05-31-2012 10:46 AM ET (US)     Profile for Sfef84  Send Email to Sfef84     
Thanks Jim,

Does anyone know to what decimal one can enter in the "fuel used" for the HDS? Reason for asking is that gas stations register to the thousandth. So, instead of filling a 5 gallon tank with water and eyeing it one can fill the gas can at the gas station and know that the total volume is say 5.085.

Jim, I agree with you that water would be the safest and cheapest way. The only problem is getting an exact measurement when filling with a hose.

6992WHALER posted 05-31-2012 01:12 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
Interesting idea.

I have a Navman 3100 fuel flow meter.
I also have electric primer pumps. Taking your idea, I could disconnect the fuel hose at the engine and put the hose in a 6 gallon fuel tank. I could then run the primer pump till the 6 gallon tank is full.

Sounds like a lot less hassle and cheaper than hooking up a 6 gallon tank in place of the main tank and running the gas through the engine.

jimh posted 05-31-2012 01:45 PM ET (US)     Profile for jimh  Send Email to jimh     
Re using water to calibrate:

First, I have pointed out that water has a different density than gasoline, and perhaps this would affect the calibration of the flow sensor, but, let's ignore that for the sake of the rest of the discussion.

I would find a container with a precision volume marking. Let's say a five gallon container. Then using water I would fill the container to the mark, and then pour the precise volume into the test fixture with the flow sensor. The outflow could just be sent to waste, on the ground or into the sea, or could be used to fill a second container. The process can be repeated as much as necessary to get the sensor volume measurement to a quantity where any error would be easily seen. The error could be corrected, and the test repeated. Water is much cheaper to use than gasoline, and it is also safer. I don't know about the calibration accuracy with a liquid of different density. Perhaps the make of the sensor could offer advice.

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