AVL iCAL Emission Calibration Devices

Accuracy through innovation

The iCAL product line includes everything you need to accurately calibrate emission measurement devices according to the legal obligations of global markets. 


AVL iCAL GDU SlimLine (SL) Gas Dividers are used to verify the linearity of analyzers used for emission certification and R&D testing. The integrated converter tester (iCAL GDU/GNU SL) determines the efficiency of NOX converters used in chemiluminescence detector (CLD) analyzers. The iCAL CFO SL propane injection tester is ideal for testing for compliance with regulatory demands for frequent Critical Flow Orifice (CFO) testing. The AVL iCAL LFE (Laminar Flow Element) includes accurate sensors for temperature and pressure and is used to calibrate critical flow venturis and mass flow controllers (MFCs). The iCAL HBU Heated Bubbler is applied for quality checks such as a sample dryer and a CLD quench verification.

The accuracy of exhaust measurement systems is highly dependent on the quality and precision of the calibration devices used. In order to guarantee high quality results, minimize operating errors and reduce operating times, we have created the AVL iCAL product line of emission calibration devices, including slim solutions for crowded test fields, such as the AVL iCAL SL (SlimLine) Gas Dividers and CFO Testers. 
AVL’s ISO 17025 accredited calibration laboratory and numerous installations at regulatory bodies demonstrate the highest levels of accuracy required to determine compliance with the complex regulatory requirements.

iCAL calibration emission device

Combined Functionality for More Space

To further ease the pressure on crowded test labs, the AVL iCAL GNU SL combines a NOx converter checker with the AVL iCAL GDU SL Gas Divider. The SL (SlimLine) devices take up as little floor space as possible. Being about half the size of other calibration devices on the market, they can even be wall mounted. In addition, we have set new benchmarks in crucial characteristics. These include:
•    Improved performance for problematic or sticky gasses, such as NH3
•    Modern, web-based, stand-alone operation
•    Fastest purge times to reduce calibration time, gas consumption and improve results

Property Unit

Voltage supply

100, 120, 230 V AC
Gas divider and CFO principle Calibrated critical nozzles
Number of GDU cut points 15, 63, 255, 1023
Converter principle  Ozone generation by corona discharge
CFO flow rate range 10 - 10,000 ml/min (depending on model)
LFE flow rate range 1 – 16 or 1- 40 m³/min 


GNU SL external

The accuracy of exhaust analysis systems is highly dependent on the calibration equipment used to calibrate them. AVL has therefore developed the most precise calibration devices available on the emission market worldwide. The key benefits are: 

Reliable Operation

Achieve best reproducibility and long-term stability

Innovative Design

New internal flow design for fast, perfect span gas purge

Easy Handling

Intuitive and fully automated operation plus modern web-based stand-alone operation

Minimized Costs

Balancing high quality with cost-effectiveness

Fully Compliant

Ensuring full ISO 17025 / EPA CFR 40 part 1065 / 1066 compliance

iCAL Gas Divider SL

Designed to generate highly accurate gas mixtures, our iCAL Gas Dividers SL have the highest number of cut points (1023) which reduces the number of span gas bottles you require. They offer the best long-term stability and reproducibility thanks to the use of highly accurate sonic nozzles.

Converter Tester

The iCAL NOx converter tester reliably determines the efficiency of NOx converters used in chemiluminescence detector (CLD) analyzers. The converter tester is built into the gas divider and is based on corona discharge technology. It is optimized for a high stability of the generated NO2 and a short stabilization time.


To comply with regulatory demands for frequent CFO (Critical Flow Orifice) testing, we have created the iCAL CFO SL propane injection tester. It allows the introduction of a precise quantity of propane into the CVS system or into a SHED chamber. To make it even more accurate, it is temperature-stabilized at 50°C.


The AVL iCAL LFE (Laminar Flow Element) includes accurate temperature and pressure sensors and a user interface. Depending on the flow range, it enables the calibration of the flow rate of either the Critical Flow Venturis within a CVS system or the Mass-Flow Controllers in a Particulate Sampler (PSS). The sensors are connected to the flow calculation unit, which saves up to five calibration coefficients.


The iCAL HBU (Heated Bubbler Unit) is used to humidify air or test gases for the execution of quality checks on exhaust gas measurement systems. A chilled mirror hygrometer is used for a precise dew point determination. It is used to perform sample dryer and CLD quench verifications according to the EPA 40 CFR part 1065/1066 regulations.

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