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AVL iCAL Emission Calibration Devices

The AVL iCAL product line includes gas dividers and NOX converter testers as well as CFO (Critical Flow Orifice) and LFE (Laminar Flow Element) devices.


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AVL Approach

The accuracy of exhaust measurement systems is highly dependent on the quality and precision of the calibration devices used. In order to guarantee the highest quality, to minimize operating errors and to reduce operating times, the devices are available in a fully automated version.


Benefits at a Glance

  • Pressure-independent flow stability
  • Plug and play integration
  • Simple use and operation
  • Extraordinary long-term stability
  • Factory-calibrated and individually certified, NIST traceable

Market Requirements

The accuracy of exhaust measurement systems is highly dependent on the quality and precision of the calibration devices used. In order to guarantee highest quality, to minimize operating errors and to reduce operating times, the AVL iCAL devices are available in a fully automated version.


Functions

The AVL Gas Divider Unit (GDU) iCAL GDU is a precision tool that provides accurate calibrations for any type of gas used in automotive applications. It is designed for long-term stability, superb accuracy, and easy operation. The AVL iCAL GDU is available with 15, 63 or 255 dilution steps plus zero step. The underlying physical principle of the device is based on the combination of calibrated critical (sonic) nozzles allowing dilute span gases. The sonic nozzles are flow calibrated with an accuracy of better than 0.4% for each dilution step. Calibration gas and dilution gas pressures are controlled with high-precision pressure regulators incorporating excellent long-term stability. A serial interface (RS232) as well as a LAN interface (TCP/IP), based on the AK standard are included for remote control.

The AVL NOX Generator Unit (NGU) iCAL NGU is utilized by automotive emission measurement systems to check the efficiency of NOX converters used in CLD analyzers. The converter tester technology is based on the gas phase titration between NO and O3, generated by corona discharge in an atmosphere of pure oxygen (O2) or synthetic air, providing known concentrations of nitrous dioxide (NO2). The AVL iCAL NGU has remote control capability to allow automated test procedures. It is optimized for a high stability of the generated NO2 and a short stabilization time.

The iCAL CFO propane injection tester is used to introduce a precise quantity (e.g. propane) into the CVS dilution system or into a SHED chamber. The injected quantity is compared to the mass measurement of the CVS dilution system or the SHED chamber. For improved accuracy, the AVL iCAL CFO is temperature stabilized at 50 °C. Most regulations require the regular implementation of this CFO test.

The AVL iCAL LFE is an optimized valve matrix, including accurate sensors for temperature and pressure as well as an electronic unit with user interface, to calibrate the flow rate of either critical flow venturis (CFV) within a CVS system or mass flow controllers (MFC) used in a particulate sampler. The pressure and temperature sensors are directly connected to the electronic flow calculation unit which can save up to 5 different, selectable LFE calibration coefficients.


Technical Data


Applications

Gas dividers are designed to verify the linearity of analyzers, while NOX converter testers are used to verify the efficiency of NOX converters in CLD analyzers.

System leak check devices, such as a CFO, are designed to verify the density of a gas path from the tailpipe up to the CVS system or a SHED chamber.

A laminar flow element (LFE) is used for the flow calibration of critical flow venturis of a CVS or mass flow controllers of a particulate sampler.

These verifications are mandatory for emission testing. The frequency of these verifications is highly dependent on the respective legislation and whether the system is used for certification or R&D testing.


Available Types

The AVL Gas Divider NOX Generator Unit (GNU) iCAL GNU combines an iCAL GDU with an iCAL NGU in a single housing. Modules with 15, 63 and 255 dilution steps plus zero step are available.

iCALGDU and iCAL GNU modules can be either integrated into an emission bench or can be used as stand-alone devices equipped with a front panel and display.

The following models are available:

External gas divider units

  • External gas dvider unit iCAL GDU 15 steps plus zero step
  • External gas dvider unit iCAL GDU 63 steps plus zero step
  • External gas dvider unit iCAL GDU 255 steps plus zero step

Internal gas divider units

  • Internal gas divider unit iCAL GDU 15 steps plus zero step
  • Internal gas divider unit iCAL GDU 63 steps plus zero step
  • Internal gas divider unit iCAL GDU 255 steps plus zero step

Internal NOX generator unit

  • Internal NOX generator unit iCAL NGU

External gas divider and NOX generator unit

  • External gas divider and NOX generator unit iCAL GNU 15 steps plus zero step
  • External gas divider and NOX generator unit iCAL GNU 63 steps plus zero step
  • External gas divider and NOX generator unit iCAL GNU 255 steps plus zero step

Internal gas divider and NOX generator unit

  • Internal gas divider and NOX generator unit iCAL GNU 15 steps plus zero step
  • Internal gas divider and NOX generator unit iCAL GNU 63 steps plus zero step
  • Internal gas divider and NOX generator unit iCAL GNU 255 steps plus zero step

The AVL iCAL CFO is available either for one span gas (propane) or for two span gases (propane, CO) and can be used for light and heavy-duty applications. Special devices are available for low emission applications.

  • iCAL CFO LD for 1 span gas
  • iCAL CFO LD for 2 span gases
  • iCAL CFO LE for 1 span gas
  • iCAL CFO LE for 2 span gases
  • iCAL CFO HD for 1 span gas
  • iCAL CFO HD for 2 span gases

The AVL iCAL LFE is designed for the calibration of either critical flow venturis (CVS system) or mass flow controllers (particulate sampler).

  • iCAL LFE CVS LD
  • iCAL LFE CVS HD
  • iCAL LFE PSS