Smog Inspection

What is a smog inspection?

A smog check is also called a vehicle emissions test or exhaust emission test. Since 2006, it has officially been called in Germany: engine management/exhaust gas cleaning system examination. At the same time the exhaust emission test for motorbikes was also introduced. Since 2010, it has been an integral part of the main inspection of motor vehicles.

A smog inspection is carried out by a state-certified organisation (e.g. TÜV Nord, TÜV Süd, Dekra, KÜS) to determine whether the emissions of a vehicle are within the values set by the state regulatory authority.

If a amog check inspection comes up negative, the workshop begins to investigate the cause. If the cause has been remedied, a follow-up check can be carried out. If the exhaust values remain above the permitted limits, this can lead to the withdrawal of the operating licence due to non-compliance with environmental requirements.

This article deals with:

1. The 3 exhaust smog inspection procedures

2. Follow the smog inspection with checklist

3. A digital solution for documenting the smog check inspection

The 3 exhaust smog isnpection procedures

In addition to the main inspection for brakes or lights, a motor vehicle must undergo an optional smog check as standard - regardless of the pollutant class. State regulations stipulate that a vehicle must undergo an exhaust smog inspectionevery two years. If a car is new, it has to undergo the main and exhaust smog check for the first time after three years.

Oldtimers are partially exempt from the obligation to undergo an exhaust smog check inspection Oldtimers with petrol engines do not have to undergo a smog inspection if they were registered before 1 July 1969. Diesel vehicles do not have to undergo an exhaust smog check t if they were first registered before 1 January 1977.

The exhaust smog check inspection has been mandatory for 30 years - and not without reason. The Federal Environment Agency regulates vehicle emissions in Germany. It created the exhaust smog check inspection to keep vehicle emissions under control and to monitor their negative effects. Particularly, health, the environment, but also the economy suffers from exhaust emissions.

There are three procedures that the inspectors perform during every smog check:

1. Pre-test

Prior to each vehicle inspection, a pre-test shall be carried out by the examiners to ensure that the test equipment has been maintained and calibrated according to its specifications.

2. Emission measurement

The responsible testers measure and record the levels of hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NOx) from vehicle emissions. While testing equipment may vary by facility, technicians always use government-approved exhaust gas analysers.

3. Visual and functional inspection

The inspectors perform a visual and functional inspection of the vehicle to check for tampered, missing, disabled, modified or defective emission control systems. They also check whether other devices, such as the malfunction indicator light, are working.

For all three procedures, inspectors can use a checklist to assist with the smog inspection. It helps to carry out all tests step by step in the correct order, to record findings and to document observations that indicate unsafe vehicle conditions or non-compliance with regulations.

The smog inspection with checklist

During the smog check inspection test, the exhaust gases of the motor vehicle are checked when it is idling. The test centres receive the corresponding reference values from the legislator as target data. The target data depend on the vehicle type and model.

In addition, the car manufacturers have the possibility to undercut the values of the legislator by stricter specifications. In this case, the inspectors use the stricter values for the smog check inspection. For this purpose, they are given access to various databases.

All guideline values, whether from the legislator or the automotive industry, are adjusted at regular intervals.

During the test, the vehicle is started to measure the level of carbon monoxide and other chemical compounds. For this purpose, a probe is placed in the exhaust. Measurements are taken at idle and increased idle.

Since the smog check inspection is part of the general inspection, the values determined are first recorded in a checklist in order to compare them with the target values of the manufacturer or the legislator after all tests have been completed. The checklist also has the advantage that all-important data about the vehicle, from the vehicle owner to the registration, are recorded in one document. This minimizes the error rate.

For vehicles with on-board computers, the exhaust smog check inspection can also be carried out as a so-called "On Board Diagnosis" (OBD). In this case, the memory is read out and the tester no longer has to insert a probe into the exhaust pipe.

A digital solution for smog check inspection

Emission testing centres are responsible for an exhaust smog check inspection. The use of paper-based emissions inspection checklists for regular registration renewals is inefficient and non-transparent. Lumiform, the mobile and powerful inspection app, helps inspectors with:

• Capture required vehicle data and optionally add photos.
• Record results efficiently and generate smog inspection reports automatically.
• Use the inspection app with other programmes and systems for exhaust smog testing.
• Customise the smog inspection checklists easily, according to local legal requirements.
• Make internal processes more efficient: Through more efficient communication within the team, with third parties and with management, as well as faster incident reporting, incidents that occur are resolved up to 4x faster than before.
• With easier analysis of all data and faster identification of areas that need attention, time is saved.