Author Topic: Fuel Strip Sensor Realtme Values  (Read 757 times)

Joe-T

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Fuel Strip Sensor Realtme Values
« on: August 17, 2018, 08:57:48 AM »
Hej folks,

a while ago I've noticed an inconsistency within the realtime values for the fuel strip sensor.

While doing some analysis (having had the "usual" fuel strip problem) I noticed that the Fuel strip heater voltage would not always show reasonable values compared to my voltmeter reading.
The maximum value seemed to be limited to 1.51V while the voltmeter reads e.g. about 5.7 Volts at the same time.

Attached diagrams indicate that a fuel level measurement runs in three consecutive phases repeatedly cycled through by the ZFE control unit. The heating voltage (across pins 4 and 1) is fairly stable within each phase and transits to the next level inbetween phases.
Thus, when looking at the corresponding realtime values in the software: The numbers also remain fairly stable until a phase change and then "suddenly" change.

The measurement phases are:
  • An initial "pre-heating" phase initiating a measurement cycle. (5s duration and heating element voltage about 0.75V)
  • The heating phase. (min. 7s max 32s duration observed; heater element voltage depending on fuel level (here ~5.7V)
  • The OFF/cooling phase. (30s duration, heater voltage about 0.06V)
Well, here's the Fuel strip heater voltage I've measured compared to what the GS-911 application shows:

Phase
measured [V] Fuel strip heater voltage [V]Film sensor heating [%] Duration
OFF / cooling down phase
0.065 V
0.07 V
0.00%
30s
pre-heating phase
0.746 V
0.76 V
8.00%
5s
heating phase (measurment)
~5.7 V
1.51 V
51.20%
7s .. 32s

While the entries for the phases in line one and two look consistent and reasonable the third one does not!
The displayed 1.51 V does not match up with the measurement nor with the percentage or current indicated by the GS-911 software.

I've e-mailed HEX Code with this issue and they opened up a ticket #19785940 for it.
However they do not have a bike with a fuel strip level sensor available to verify and possibly reproduce the issue on a different bike.

Can you help and post the maximum realtime value for the "Fuel strip heater voltage" as reported via the GS-911?

How to get there : ZFE > Realtime Values > Fuel strip heater voltage
Do you see any value above 2 V within an observation time  of 1 .. 2 minutes ? I'll appriciate any fedback positiv and negative !!

If you really want to do us a favour for the analysis, you may provide readings for the following fuel strip realtime values or a short log csv file (~2 min)! This would be much appriciated!
  • Fuel strip heater current
  • Fuel strip heater voltage
  • Film sensor heating %
  • Fuel sense voltage
How to do it?:
  • Hook up your GS-911 to your bike and turn the ignition on.
  • Run the GS-911 application, select your bike, enter the ZFE control unit menue and
  • Select above listed fuel sensor realtime values (and perhaps the battery voltage to monitor).
  • Monitor and note the Fuel strip heater voltage for all three measurement phases. - Or the easier way:
  • Activate csv logging for about a  2 minutes then deactivate and post the csv file.

Thanks, Joe

Note:
Attached diagrams are only visible when logged in.
« Last Edit: August 18, 2018, 11:33:49 AM by Joe-T »