Differential fuel flow meter
DFM D differential fuel flow meter is designed for diesel fuel consumption measurement in fuel lines of vehicles and stationary engines, and is used as part of GPS vehicle tracking system. In addition, DFM D registers working time of engine in various modes of operation. DFM D is used for consumption monitoring of:
- diesel fuel;
- heating oil;
- other types of liquid fuel with a kinematic viscosity of 1.5 to 6 mm2/ s.
DFM D fuel flow meters, which re equipped with display, are used as a stand-alone (autonomous) solution for accounting fuel consumption, not requiring any connection to a web-server. DFM D are more suitable for modern engines (Common rail or pump injector fuel systems) of vehicles and stationary units.
Tasks
Preventing fuel theft
Engine testing for fuel consumption
Machine running time trackingAdvantages of DFM D
Differential measurement of fuel consumption
DFM D has two measuring chambers for supply and return fuel lines. The flowmeter measures fuel consumption in each line and computes the difference between supply and return. The result is stored in an appropriate Counter. Values of Counters are sent to telematics (monitoring) unit as digital messages (for DFM with RS232, RS485 or CAN output).
Built-in battery
In case of absence of an external power source, for example, from the on-board network, DFM keeps on to register data to the internal memory. When external power is restored, all accumulated data will be transferred to the on-board monitoring terminal.
Replaceable mud filter
Installed in the inlet of DFM D. Protects flow meter supply chamber from particles of dirt and sand, which went through fine filter. The mud filter significantly increases reliability and durability of the flowmeter. The filter is replaced “on site”, without a need of disassembly-assembly operations and additional verification of flowmeter accuracy and body integrity.
Fuel consumption and operating time Counters
Fuel consumption
- Instant fuel consumption, L/H
- Hourly fuel consumption in “Forward” line
- Hourly fuel consumption in “Return” line
- Total fuel consumption, L
- Total fuel consumption in “Idling” mode of engine operation
- Total fuel consumption in “Optimal” mode of engine operation
- Total fuel consumption in “Overload” mode of engine operation
- Total fuel consumption in “Negative” mode of flow meter operation (return exceeds supply)
Engine operating time
- Total operating time, h
- Total operating time in “Idling” engine operation mode
- Total operating time in “Optimal” engine operation mode
- Total operating time in “Overload” engine operation mode
- Total operating time in “Negative” flow meter operation mode
- Total operating time of Supply chamber
- Total operating time of Return chamber
- Operating time of Supply and Return chambers in each mode of engine operation
Special
- Engine operating time in “Tampering” mode, h
- Engine operating time in “Interference” mode, h
- Current engine operation mode as per fuel consumption rate
- Fuel temperature
- Temperature correction status
- Correction coefficient value
- Battery charge
DFM D types
DFM CD differential (two-chamber) fuel counter
DFM D differential fuel flow meter with output signal cable
Differential fuel flow meter installation and connection
Differential fuel flow meter are installed in both line of fuel system – supply (feed) and return. Each chamber of DFM D is connected to an appropriate line, chambers are marked “F” for feed line and “R” for return line. Exact place of flow meter installation depends on fuel system specifications of particular vehicle. For general guidance, please, refer to DFM Operation Manual.
It is possible to install several DFM D and connect them to telematics unit via a single cable – it is especially useful for machinery equipped with more than one fuel consuming units (e.g. river boat has two propelling motors, boiler, diesel generators and other auxiliary systems). For more information, please, refer to CAN/S6 telematics interface page.
Accessories for installation of DFM D flow meters
| Connecting thread | M14x1.5 |
| Nominal pressure, bar | 2 |
| MAX pressure, bar | 25 |
| Supply voltage, V | 10-45 |
| Overvoltage protection, V | ≤100 |
| Current consumption, mA (24 V/12 V), mA | 25 / 50 |
| Operating temperature, (without/with display), °C | -40..+85/ |
| -20..+60 | |
| Ingress Protection Rating | IP54 |
| Relative accuracy error per chamber, %, not more than | 1 |
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DFM modifications
Following DFM types are available:
- fuel flow meters with display, one-chamber or differential);
- fuel flow meters without display, one-chamber or differential).
* A symbol is not specified for differential fuel flow meters.
** For autonomous fuel flow meters Z version is not used.
*** This version is delivered upon special order. Designation U is available only for one-chamber flowmeters.
Output signals (specified in purchase order): pulse, digital RS232, digital RS485, digital CAN/S6
Specifications
| Connecting thread | M14x1.5 |
| Nominal pressure, bar | 2 |
| MAX pressure, bar | 25 |
| Supply voltage, V | 10-45 |
| Overvoltage protection, V | ≤100 |
| Current consumption, mA (24 V/12 V), mA | 25 / 50 |
| Operating temperature, (without/with display), °C | -40..+85 -20..+60 |
| Ingress Protection Rating | IP54 |
| Relative accuracy error per chamber, %, not more than | 1 |
Models
DFM 100D / 100 l/h
DFM 250D / 250 l/h
DFM 500D / 500 l/h
DFM modifications
Following DFM types are available:
- fuel flow meters with display, one-chamber or differential);
- fuel flow meters without display, one-chamber or differential).
* A symbol is not specified for differential fuel flow meters.
** For autonomous fuel flow meters Z version is not used.
*** This version is delivered upon special order. Designation U is available only for one-chamber flowmeters.
Output signals (specified in purchase order): pulse, digital RS232, digital RS485, digital CAN/S6
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