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AVL PLU131 Flow Measurement Systems

AVL PLU131 Flow Measurement Systems are high-precision flow meters and flow measurement systems for injector, pump or control valve characterization in production, R&D and engine application.

AVL Approach

AVL provides a large spectrum of flow sensors and system solutions for these tasks with either continuous flow rate metering or injection quantity measurement.

R&D
R&D applications focus on component characterization and validation under a wide range of operation conditions.
Injection quantity measurement and injection rate analysis on component and system test benches. The most prominent group of test objects is fuel injectors (CR, GDI, Port Fuel Injectors, Unit Injectors, SCR Injectors etc.; solenoid and piezo) and fuel injection systems.

Injector testing includes injection quantity characterization versus parameters as energizing time, pressure or temperature (Q(ti,p,T). But it also comprises analysis of needle movement and timing (open and closing) as well as injection rate shaping etc.

Injection system testing investigates multiple injector interaction in a complete engine injection system. Pressure wave compensation, for instance, investigates mutual influence on flow characteristics depending on pressure and engine speed.

Production
Component manufacturing requires quality control, adjustment or calibration of mass products like injectors, pumps, control valves etc. Sample checking or 100% control of flow characteristics is mostly realized via continuous flow measurement where short measurement time and high reliability are the most important features.


Benefits at a Glance

  • Test time reduction: higher accuracy reduces averaging time
  • Process acceleration in R&D : reliable characterization and fast verification of progress
  • Cost reduction in application: engine map pre-calibration reduces engine test bed time
  • High reliability: robust sensors and extreme long-term stability of the calibration due to PLU measurement principle

Market Requirements

Production testing for diesel and gasoline fuel injectors includes a variety of integrated measurement solutions ranging from random inspection on semi-automated test benches to 100% control on fully automated production lines. Similar manufacturing test requirements apply to fuel pumps and control valves. R&D and engine applications add further tasks as flow characteristic verification, injector timing map calibration or combustion development.


Technical Data

AVL PLU 131 Flow Sensor Specifications

 

STS PLU 131 Fuel

STS PLU 131 Urea

PLU 131F

PLU 131S

Sensor type

Injection rate and quantity measurement sensor including high-speed data acquisition system

Average flow rate

Typical applications

High pressure direct fuel injection component and 
system testing in R&D, production, engine application, racing, etc.

SCR injector and dosing system testing in R&D 
and production



 

Low pressure fuel injector and fuel pump production 
testing; high-precision 
fuel flow- measurement in 
R&D

High temperature or high 
pressure fuel injector and 
fuel pump production 
testing

Standard 
configuration

Downstream or Upstream

Upstream

Measurement parameters

Flow rate, injection rate and quantity with up to 12 partial injections, injector current, injector opening and closing delays, pressure, temperature

 

Momentary flow rate, total consumption and statistical data in combination with data acquisition system


 

Measurement range

   Flow rate

0.01 ... 10 l/h

0.01 ... 10 l/h

0.05 ... 10 l/h

0.05 -10 l/h

 

0.02 ... 20 l/h

0.02 ... 20 l/h

0.05 ... 20 l/h

0.05 - 20 l/h

 

0.04 ... 40 l/h

 0.04 ... 40 l/h

0.1 ... 40 l/h

0.1 - 40 l/h

 

 

 

0.15 ... 75 l/h

0.2 - 80 l/h

 

 

 

0.3 ... 150 l/h

0.3 - 150 l/h

 

 

 

0.8 ... 300 l/h

0.8 - 300 l/h

   Injection
   quantity

0.1 ... 600 mm³

0.1 ... 600 mm³

 

 

Measurement uncertainty

 

 

 

 

   Flow rate*)

0.1 %

0.1 %

0.1 %

0.1 %

   Total
   measure-
   ment 
   uncertainty**)

1 % at > 2 mm³
shot volume

1 % at > 10 mm³ shot volume and 4 Hz cycle rate

 

 

Cycle rate

10 ... 180 Hz

1 ... 10 Hz

 

 

Dynamic response time acc. DIN 19226

 

 

<100 ms

<100 ms

Media

Common gasoline and 
Diesel fuels and 
compatible test media; alcoholic additives up to 
100 %

 

Aqueous urea solution according to ISO22241 2008/9 (AdBlue®) ***),
De-ionized water with 1 % Prevox  or 50% ethylene glycol ****)

Common gasoline and 
Diesel fuels and 
compatible test media; alcoholic additives up to
100 %

 

Common gasoline and 
Diesel fuels and 
compatible test media; alcoholic additives up to 100 %
 

Density

0.69 ... 0.85
g/cm³

0.99 ... 1.19
g/cm³

0.69 ... 0.85
g/cm³

0.69 ... 0.85
g/cm³

 

Further media densities upon request

Operating temperature

   Media

-30 - +70 °C

+10 - +60 °C

-20 - +70 °C

-30 - +70 °C

   Environment

-30 - +60 °C

+10 - +60 °C

-20 - +60 °C

-30 - +60 °C

 

Up to 150 °C with optional cooling flange

 

 

Up to 150 °C with optional cooling flange

Operating pressure

0.01 - 200 bar

0.01 - 10 bar

0.1 - 10 bar

0.01 - 200 bar

   Differential
   pressure

ΔP=0 (PLU measurement principle)

   Back
   pressure

No minimum back pressure required

Interfaces

Frequency
(max. 150 kHz)

Frequency
(max. 150 kHz)

Frequency
(max. 70 kHz)

Frequency (max.150 kHz)

Power supply

100 - 240 V AC
50/60 Hz
(STS Control Unit)

100 - 240 V AC
50/60 Hz
(STS Control Unit)

24 V - 40 V DC

24 V - 40 V DC

Power consumption

Max. 50 W

Max. 50 W

Max. 40 Watt

Max. 40 Watt

Sensor dimensions 
(W x H x D)

335 x 216 x 140mm
(W x D x H )
363 x 216 x 140mm
(W x D x H )
including cooling flange

335 x 216 x 140mm
(W x D x H )

340 x 216 x 133 mm

335 x 216 x 140mm
(W x D x H )
363 x 216 x 140mm
(W x D x H ) including cooling flange

Sensor weight

16 kg

15 kg

10 kg

14 kg

Protection

 

 

Ex II 2G EEx d IIB T6

Ex II 2 G  EEx d IIB T6 acc. EN 50 018:1994, EN 50 014:1997

Safety

CE

CE

CE

CE

Calibration

Traceable back to German national standard (PTB)

 
*) Measurement uncertainty of flow meter calibration factors under repeatable conditions with medium HAKU at 20 °C and 1 bar
**) Total measuring uncertainty acc. GUM ( Guide to the Expression of Uncertainty in Measurement ) for an optimized injection system 
***) AdBlue® is a trademark of the VDA for the official name Urea AUS 32 according to ISO 22241 2008/9
****) De-ionized water solution with 1% P3-Prevox 7400 (99/1 vol%) or with 50% ethylene glycol (50/50 vol%)


System Scope

Continuous Fuel Flow Measurement
Fuel pumps, control valves and diesel and gasoline low pressure injectors are typically tested in operation as a final step in the production process. Average fuel flow quantity examination over a characteristic flow range is used as performance check for the devices.

For this purpose AVL offers the PLU131 flow sensor family with the following features:

  • High-accuracy continuous fuel flow meters for a wide temperature and pressure range

  • Large measuring range up to 1:500 at high resolution provide for short measurement time

  • Extreme sensor robustness and long-term stability of calibration


 

Fuel Injection Quantity Measurement
High pressure systems for direct fuel injection like common rail diesel or GDI require cycle-resolved shot quantity measurement for performance examination as well as for production quality check, featuring:

  • Shortest measurement time for flow characteristic verification in end-of-line testing

R&D applications include further tasks in injector and system characterization, such as:

  • Crank-angle resolved injection rate analysis for combustion development

  • Precise shot measurement of multiple injections for injection system pressure wave compensation and injection timing map calibration

With the Shot-to-Shot™, PLU131 AVL provides a state-of-the-art shot measurement system compliant with the most extreme requirements of OEMs and component suppliers.


 

Aqueous media (AdBlue®) and extremely low flow rate
Low pressure injection systems are used for diesel engine exhaust aftertreatment in SCR systems for NOx reduction and HC dosers for DPF regeneration. Extremely low flow rates and small dosing quantities are particular challenges for characterization and performance testing of these dosing systems. AVL offers system solutions that are well adapted to these special requirements.


System Integration Service
AVL provides integration support to system integrators as well as end users for the full range of flow sensors and system solutions and for a variety of measurement tasks.



Measuring Principle

PLU Measurement Principle
AVL PLU sensors combine the most suitable measurement technology for these specific applications with high reliability and extreme long-term stability of the calibration.

The PLU measurement principle offers a number of advantages:

  • Extremely large measuring range of up to 1:1000
  • High accuracy even at very low flow rates <10g/h
  • No pressure drop (Δp=0) and consequently no influence on the dosing system
  • No leakage over the gear counter due to (Δp=0)

The PLU measurement principle, with two independent positive displacement sensors, combines the highly dynamic sensitivity of a piston sensor with the extremely robust accuracy of a servo-controlled gear meter. It prevents any interference of the flow meter with the hydraulic system to be measured. The sensor cancels out the pressure difference (ΔP=0) between inlet and outlet, avoiding leakage alongside the gears.