Oxygen Sensor Tester model ST05

Autotechnique - France

General Technologies Corp,G T C is pleased to announce the appointment of Autotechnique as distributors in France.

Autotechnique a été créé par David Paterson, un ancien technicien automobile et garagiste avec une expérience longue et variée dans l'industrie d'automobile et le transport. Après un apprentissage en tant que mécanicien dans un garage de marque Rolls Royce, il a complété sa formation de technicien/électricien dans l'armée avec REME (Royal Electrical and Mechanical Engineers).

Autotechnique was created by David Paterson, a former vehicle technician and garage proprietor with a long and varied experience of the motor and transport industries. After first training as an apprentice mechanic with a Rolls Royce garage, he completed his training as a vehicle technician/electrician with REME (Royal Electrical and Mechanical Engineers).

David a continué sa carrière en fabriquant des voitures de course; il a développé un marché de moteurs échange standard; il a travaillé comme spécialiste en diagnostic de moteurs et de carburateurs. Son intérêt principal a été le fonctionnement des voitures et le processus de diagnostic en cas de dysfonctionnement. Il a également écrit des articles techniques pour des magazines spécialisés et des journaux. David est aujourd'hui persuadé que chacun a besoin d'être formé et équipé correctement pour diagnostiquer les pannes efficacement et précisément.

David went on to build and maintain racing cars; to market remanufactured engines; and later to specialise in engine tuning. His main interest has been in 'how things work' and how to diagnose them when they don't. He's written several magazine and newspaper articles, and believes strongly in the need for training and in being properly equipped to take on the task of diagnosing faults accurately.

Avant de créer Autotechnique, il a effectué plus de deux ans de recherche concernant le marché des appareils de diagnostic; il est allé directement chez les fabricants de différents pays et a complété sa formation par différents stages chez ces mêmes fabricants.

Before forming Autotechnique, he completed more than two years of research into the vehicle diagnostic equipment market - visiting factories in several different countries, and attending factory training courses.

Autotechnique

Autotechnique
29 Carrer Major
66320 Finestret
France

Tel: + 33 4 68 964 815
Fax: + 33 4 88 920 512
contact@autotechnique.fr

Go GREEN - Make Oxygen sensor testing part of your service menu

ST05 – Oxygen Sensor Tester

With the ever increasing fuel costs, you want to be sure your customers are not
using more fuel than they need to!
The ST05 is a professional oxygen sensor tester that allows Technicians to test Zirconium,Titanium 1 volt and 5 volt oxygen sensors; both heated or unheated (1 to 4 wires).
The ST05 is a quick and easy to operate tool that gives a pass or fail result in a matter of seconds.
It is very simple to hook up and operate. See details at www.gtc.ca

Go GREEN – Make testing of ALL oxygen sensors part of your regular service.

A faulty oxygen sensor could contribute to excessive fuel consumption. Be certain your customer’s cars are performing correctly by testing oxygen sensors and replacing faulty units.
Don’t forget, the savings from 6- 8 fills of a 65 litre tank would pay for the sensor.

Oxygen Sensors - a historical view....

An oxygen sensor, or lambda sensor, is an electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed. It was developed by Robert Bosch GmbH in Germany during the late 1960s under supervision by Dr. Günter Bauman. The original sensing element is made with a thimble-shaped zirconia ceramic coated on both the exhaust and reference sides with a thin layer of platinum and comes in both heated and unheated forms. The planar-style sensor entered the market in 1998 (also pioneered by Robert Bosch GmbH) and significantly reduced the mass of the ceramic sensing element as well as incorporating the heater within the ceramic structure. This resulted in a sensor that both started operating sooner and responded faster. The most common application is to measure the exhaust gas concentration of oxygen for internal combustion engines in automobiles and other vehicles.

Automotive Applications

Automotive oxygen sensors, colloquially known as O2 sensors, make modern electronic fuel injection and emission control possible. They determine if the air fuel ratio exiting a gas-combustion engine is rich (with unburnt fuel vapor) or lean (with excess oxygen). Closed-loop feedback-controlled fuel injection varies the fuel injector output according to real-time sensor data rather than operating with a predetermined (open-loop) fuel map. In addition to improving overall engine operation, they reduce the amounts of both unburnt fuel and oxides of nitrogen from entering the atmosphere. Unburnt fuel is pollution in the form of air-borne hydrocarbons, while oxides of nitrogen (NOx gases) are a result of excess air in the fuel mixture and cause smog and acid rain. Volvo was the first automobile manufacturer to employ this technology in the late 70s, along with the 3-way catalyst.

Information on oxygen concentration is sent to the engine management computer or ECU, which adjusts the mixture to give the engine the best possible fuel economy and lowest possible exhaust emissions. Failure of these sensors, either through normal aging, the use of leaded fuels, or fuel contamination with silicones or silicates, for example, can lead to damage of an automobile's catalytic converter and expensive repairs.

Tampering with or modifying the signal that the oxygen sensor sends to the engine computer can be detrimental to emissions control and can even damage the engine. When the engine is under low-load conditions (such as when accelerating very gently, or maintaining a constant speed), it is operating in 'closed-loop mode'. This refers to a feedback loop between the fuel injectors and the oxygen sensor, to maintain stoichiometric ratio. If modifications cause the mixture to run lean, there will be a slight increase in fuel economy, but a great increase in nitrogen oxide emissions, and the risk of damaging the engine due to detonation and excessively high exhaust gas temperatures. If modifications cause the mixture to run rich, then there will be a slight increase in power, again at the risk of overheating and igniting the catalytic converter, while decreasing fuel economy and increasing hydrocarbon emissions.

When an internal combustion engine is under high load (such as when using wide-open throttle), the output of the oxygen sensor is ignored, and the engine automatically enriches the mixture to protect the engine. Any changes in the sensor output will be ignored in this state, as are changes from the air flow meter, which might otherwise lower engine performance due to the mixture being too rich or too lean, and increase the risk of engine damage due to detonation if the mixture is too lean.

Function of a lambda probe

Lambda probes are used to reduce vehicle emissions by ensuring that engines burn their fuel efficiently and cleanly. Robert Bosch GmbH introduced the first automotive lambda probe in 1976, and it was first used by Volvo and Saab in that year. The sensors were introduced in the US from about 1980, and were required on all models of cars in many countries in Europe in 1993.

By measuring the proportion of oxygen in the remaining exhaust gas, and by knowing the volume and temperature of the air entering the cylinders amongst other things, an ECU can use look-up tables to determine the amount of fuel required to burn at the stoichiometric ratio (14.7:1 air:fuel by mass for gasoline) to ensure complete combustion.

The probe

The sensor element is a ceramic cylinder plated inside and out with porous platinum electrodes; the whole assembly is protected by a metal gauze. It operates by measuring the difference in oxygen between the exhaust gas and the external air, and generates a voltage or changes its resistance depending on the difference between the two. The sensors only work effectively when heated to approximately 300°C, so most newer lambda probes have heating elements encased in the ceramic to bring the ceramic tip up to temperature quickly when the exhaust is cold. The probe typically has four wires attached to it: two for the lambda output, and two for the heater power, although some automakers use a common ground for the sensor element and heaters, resulting in three wires. Earlier non-electrically-heater sensors had one or two wires.

Zirconia sensor

The zirconium dioxide, or zirconia, lambda sensor is based on a solid-state electrochemical fuel cell called the Nernst cell. Its two electrodes provide an output voltage corresponding to the quantity of oxygen in the exhaust relative to that in the atmosphere. An output voltage of 0.2 V (200 mV) DC represents a lean mixture. That is one where the amount of oxygen entering the cylinder is sufficient to fully oxidize the carbon monoxide (CO), produced in burning the air and fuel, into carbon dioxide (CO₂). A reading of 0.8 V (800 mV) DC represents a rich mixture, one which is high in unburned fuel and low in remaining oxygen. The ideal point is 0.45 V (450 mV) DC; this is where the quantities of air and fuel are in the optimum ratio, called the stoichiometric point, and the exhaust output mainly consists of fully oxidized CO₂.

The voltage produced by the sensor is so nonlinear with respect to oxygen concentration that it is impractical for the electronic control unit (ECU) to measure intermediate values - it merely registers "lean" or "rich", and periodically adjusts the fuel/air mixture to keep the output of the sensor alternating between these two states. The time period chosen by the ECU to monitor the sensor and adjust the fuel/air mixture creates an inevitable delay, which makes this system less responsive than one using a linear sensor (see below). The shorter the time period, the higher the so-called "cross count" and the more responsive the system.

The zirconia sensor is of the 'narrow band' type, referring to the narrow range of fuel/air ratios to which it responds.

Wideband zirconia sensor

A variation on the zirconia sensor, called the 'wideband' sensor, was introduced by Robert Bosch in 1994 but is (as of 2006) used in only a few vehicles. It is based on a planar zirconia element, but also incorporates an electrochemical gas pump. An electronic circuit containing a feedback loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas. This sensor eliminates the lean-rich cycling inherent in narrow-band sensors, allowing the control unit to adjust the fuel delivery and ignition timing of the engine much more rapidly. In the automotive industry this sensor is also called a UEGO (for Universal Exhaust Gas Oxygen) sensor. UEGO sensors are also commonly used in aftermarket dyno tuning and high-performance driver air-fuel display equipment. The wideband zirconia sensor is used in stratified fuel injection systems, and can now also be used in diesel engines to satisfy the forthcoming EURO and ULEV emission limits.

Titania sensor

A less common type of narrow-band lambda sensor has a ceramic element made of titanium dioxide (titania). This type does not generate its own voltage, but changes its electrical resistance in response to the oxygen concentration. The resistance of the titania is a function of the oxygen partial pressure and the temperature. Therefore, some sensors are used with a gas temperature sensor to compensate for the resistance change due to temperature. The resistance value at any temperature is about 1/1000th the change in oxygen concentration. Luckily, at lambda = 1, there is a large change of oxygen, so the resistance change is typically 1000 times between rich and lean, depending on the temperature.

As titania is an N-type semiconductor with a structure TiO2-x, the x defects in the crystal lattice conduct the charge. So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high. The control unit feeds the sensor with a small electrical current and measures the resulting voltage across the sensor, which varies from near 0 volts to about 5 volts. Like the zirconia sensor, this type is so nonlinear that in practice it is used simply as a binary "rich or lean" indicator. Titania sensors are more expensive than zirconia sensors, but they also respond faster.

In automotive applications the titania sensor, unlike the zirconia sensor, does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.

Location of the probe in a system

The probe is typically screwed into a tapped hole in the exhaust, located after the branch manifold of the exhaust system combines, and before the catalytic converter. New vehicles are required to have a sensor before and after the exhaust catalyst to meet U.S. regulations requiring that all emissions components be monitored for failure. Pre and post-catalyst signals are monitored to determine catalyst efficiency. Additionally, some catalyst systems require brief cycles of lean (oxygen-containing) gas to load the catalyst and promote additional oxidation reduction of undesirable exhaust components.

Sensor surveillance

The air-fuel ratio and naturally, the status of the sensor, can be monitored by means of using an air-fuel ratio meter that displays the read output voltage of the sensor.

Sensor failures

Normally, the lifetime of an unheated sensor is about 30,000 to 50,000 miles. Heated sensor lifetime is typically 100,000 miles. Failure of an unheated sensor is usually caused by the buildup of soot on the ceramic element, which lengthens its response time and may cause total loss of ability to sense oxygen. For heated sensors, normal deposits are burned off during operation and failure occurs due to catalyst depletion, similar to the reason a battery stops producing current. The probe then tends to report lean mixture, the ECU enriches the mixture, the exhaust gets rich with carbon monoxide and hydrocarbons, and the mileage worsens.

Leaded gasoline contaminates the oxygen sensors and catalytic converters. Most oxygen sensors are rated for some service life in the presence of leaded gasoline but sensor life will be shortened to as little as 15,000 miles depending on the lead concentration. Lead-damaged sensors typically have their tips discolored light rusty.

Another common cause of premature failure of lambda probes is contamination of fuel with silicones (used in some sealings and greases) or silicates (used as corrosion inhibitors in some antifreezes). In this case, the deposits on the sensor are colored between shiny white and grainy light gray.

Leaks of oil into the engine may cover the probe tip with an oily black deposit, with associated loss of response.

An overly rich mixture causes buildup of black powdery deposit on the probe. This may be caused by failure of the probe itself, or by a problem elsewhere in the fuel rationing system.

The GTC ST05 Oxygen Sensor Tester/Simulator offers a convenient, easy and reliable way of checking oxygen sensors. For details on this product, please visit:
http://www.gtc.ca/EN/ST05_EN.html

WIDE BAND SENSORS - an example

How the NTK Pump Cell Sensor Works


Briefly, the NTK sensor requires a controller because it is more complex than a standard switching type sensor. It's made up of a narrow band oxygen sensor (the Reference Cell in the image) coupled to a pump cell and a small diffusion chamber. The electronics (in the WB unit case) are represented by the yellow and green symbols.

The pump cell, in conjunction with a catalytic reaction at the surface of the cell's electrodes, can either consume oxygen or consumed hydrocarbon fuel in the pump cell cavity, depending on the direction of the Ip current flow.

In normal sensor operation, a small sample of the exhaust gas passes through the diffusion gap into the pump cell. That exhaust gas is either rich or lean and both conditions are sensed by the reference cell which produces a voltage Vs above or below the Vref signal (this voltage has the characteristics of a narrow band switching type sensor).

A rich exhaust will produce a high Vs voltage and the electronics produces a pump current Ip in one direction to consume the free fuel. A lean exhaust produces a low Vs and the electronics sends the pump current in the opposite direction to consume free oxygen.

When the free oxygen or free fuel has been neutralized, the Vs feedback signal goes to about 450 m Volts (the same as the Vref value). The pump current required to produce this equilibrium is a measure of the Lambda or Air Fuel Ratio. The electronics in the WB unit converts the Ip into a V out which is the output of the WB unit. Not shown is the Rcal, or calibration resistor, in the sensor's connector which compensates for manufacturing variations between sensors.


Here are some representations of the Vs or narrow band Sense Voltage (left) and Ip or Pump Current characteristics described above. Note that the narrow band graph's x-axis covers only a very narrow lambda range (+/- 0.02), whereas the wideband's x-axis covers the range 0.9 to 2.2.




This graph shows the actual Vout of the DIY-WB unit. Note that the curve takes the same general shape as the above Ip graph.


In particular, note that the rich and lean regions have a different slope. This occurs because the chemical reactions in the rich and lean regions are fundamentally different, and the magnitude of Ip has a different effect in each region.

For product information on the GTC Oxygen Sensor Tester, please visit www.gtc.ca

Snap-On Tools Japan markets the ST05 from GTC

Snap-On Tools Japan has decided to run with the GTC ST05 Oxygen Sensor Tester in the Japanese Market.



Company: General Technologies Corp.
Product: ST05 Oxygen Sensor Tester/Simulator
This high-tech, user-friendly Oxygen Sensor Tester/Simulator from General Technologies Corp. sports a simple interface for diagnostic tests on any Oxygen Sensor to quickly determine whether the Sensor is defective and needs replacement.
It is designed as both a stand-alone tool or as a complement to any scanner during the diagnostic process.
It can be used on all sensors: Zirconium; Titanium 1 volt; Titanium 5 volt; Wide Band "dual-Cell"; and Heated or unheated (1, 2, 3, 4 or 5 wires). The ST05 is simple to set-up and use, provides fast and accurate testing, shows output signal in real time, diagnoses "Lazy" sensors which may not trigger DTC's but cause driveability problems, simulates Sensor Outputs, determines/locates faulty sensor, sensors can be tested ON or OFF vehicle.
The tester does not require time-consuming set-up or in-depth knowledge, real-time cross-count is displayed on live bar graph, and instant sensor PASS/FAIL result shown on large display.

GTC products are imported into Japan by World Auto Supply, a long time GTC distributor based in Tokyo who are responsible for all marketing aspects of the GTC products in Japan.


For more info on the GTC product line please visit: www.gtc.ca

ST05 Gets 2008 PTEN Innovation Awards Nomination

General Technologies Corp.

Product: ST05 Oxygen Sensor Tester/Simulator
This high-tech, user-friendly Oxygen Sensor Tester/Simulator from General Technologies Corp. sports a simple interface for diagnostic
tests on any Oxygen Sensor to quickly determine whether the Sensor is defective and needs replacement. It is designed as both a stand-alone
tool or as a complement to any scanner during the diagnostic process.
It can be used on all sensors: Zirconium; Titanium 1 volt; Titanium 5 volt; Wide Band "dual-Cell"; and Heated or unheated (1, 2, 3, 4 or 5 wires). The ST05 is simple to set-up and use, provides fast and accurate testing, shows output signal in real time, diagnoses "Lazy" sensors which may not trigger DTC's but cause driveability problems, simulates Sensor Outputs, determines/locates faulty sensor, sensors can be tested ON or OFF vehicle, does not require time-consuming set-up or in-depth knowledge, Real-time cross-count is displayed on live bar graph, and instant sensor PASS/FAIL result shown on large display.

Category: Diagnostic test equipment

Circle 201 on inquiry card or click “e-inquiry” at www.pten.com

For additional information on GTC products, please visit www.gtc.ca

Instant Pass/Fail for O2 Sensors from GTC

ST05 - OXYGEN SENSOR TESTER/Simulator
This high-tech, user friendly Oxygen Sensor Tester/Simulator from General Technologies Corp sports a simple interface to perform
diagnostic tests on any Oxygen Sensor to quickly determine whether the Sensor is defective and needs replacement.
It is designed to be used both, as a stand alone tool or as a compliment to any scanner during the diagnostic process.
Can be used on all oxygen sensors:
Zirconium Sensors
Titanium 1 volt sensors
Titanium 5 volt Sensors
Wide Band "dual-Cell" Sensors.
Heated or unheated Sensors (1,2,3,4 or 5 wires)
Advantages:
Simple to set-up and use
Fast and accurate testing of sensor. Output signal shown in real time on bar graph
Diagnose "Lazy" sensors which may not trigger DTC's but cause driveability problems
Simulate Sensor Outputs
Determine and locate faulty sensor
Sensor can be tested either ON or OFF vehicle
Does not require special time-consuming set-up or in-depth knowledge
Real time cross count displayed on live bar graph
Instant sensor PASS/FAIL result shown on large alpha-numeric display
Additional Features:
Rugged construction, manufactured in North America
42 V Ready
Internally protected against power surges, overloads and reversed polarity connections
Bright and powerful LED bar graph for sensor signal
Cross count displayed on 2 digit alphanumeric LED display
High temperature silicone 16 AWG test wires and rugged piercing clamps
Protective rubber holster
ST05 Oxygen Sensor Tester/Simulator comes complete with:
ST05 Tester/simulator
Protective rubber holster
Polypropylene carrying case
9 volt battery
Comprehensive User's manual.

SOME GREAT PRODUCTS

GTC Introduces New Oxygen Sensor Tester/Simulator

ST05 OXYGEN SENSOR TESTER/SIMULATOR

This high-tech, user friendly Oxygen Sensor Tester/Simulator model ST05 from General Technologies Corp/Sheffield Research sports a simple interface to perform diagnostic tests and measurements on any Oxygen Sensor and to quickly determine whether or not an Oxygen Sensor is actually defective and in need of replacement.
It is designed to be used both, as a stand alone tool or as a compliment to any scanner during the diagnostic process.
Can be used on:
Zirconium Sensors
Titanium 1 volt sensors
Titanium 5 volt Sensors
Wide Band "dual-Cell" Sensors.
Heated or unheated Sensors (1,2,3,4 or 5 wires)
Diagnose "Lazy" sensors which may not trigger DTC's but cause driveability problems
Sensors can be tested either ON or OFF vehicles.
Does not require special time-consuming set-up or in-depth knowledge
Real time cross count displayed on live bargraph
Instant PASS/FAIL results displayed on large alpha-numeric display