Air/Fuel Meters

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The HALMETER AF30 ( The wiring harness not shown in picture )
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An essential part of tuning any high performance engine is knowing whether the air fuel ratio is correct. A rich mixture will lead to a loss of power, while a lean mixture may result in detonation. The HALMETER AF30 provides a thirty LED readout of air fuel ratio, right there, in the cockpit, while you drive.

EXHAUST GAS ANALYSIS WITH THE HALMETER AND THE LAMBDA OXYGEN SENSOR

The design of the Lambda or oxygen sensor provides a signal which is easily interpreted by the HALMETER AF30. The sensor produces a small voltage output by comparing free oxygen in the exhaust gases with ambient oxygen outside the exhaust system. This voltage is created when the sensor is heated to between 360 degrees centigrade (680 F) and 900 degrees centigrade (1 650F) and varies between zero and one volt. The AF30 processes this voltage output and displays the result via a series of red, yellow and green LED's: The red lights for lean, yellow for the stoichiometric band and the green lights indicating mixtures likely to produce maximum power. It should be noted that, in the event the sensor is located in the exhaust where the temperatures are at or above the maximum, a reduced voltage output will result in fewer lights, in the green band, being lit at rich mixtures. Dividing the small output from the sensor into thirty incremental LED's gives the HALMETER AF30 superior resolution compared to other instruments of its type. More info? or e-mail us.

The HALMETER AF30 Air Fuel Ratio Indicator offers the tuner a low cost, attractive unit with thirty LED indicators that signal lean-optimum-rich.
The HALMETER AF30 Air Fuel Ratio Indicator works on all engines, carbureted or injected, and with gasoline, alcohol or propane fuels. When used with programmable EFI systems, it helps establish fuel maps and makes the mixture trim control a more precise tool for on track tuning.
The HALMETER AF30 Air Fuel Ratio Indicator kit is supplied complete with meter, wiring harness, pre heated oxygen sensor and exhaust fittings. The oxygen sensor is of a very high quality, and extremely sensitive.
Price AF30: 3695 Sek (about £255 ) including VAT and freight inside EU (European Union). Outside EU 2956 Sek. Around US£ 199Note that if you live outside EU, local taxes and duties can be added when arriving to your country! Payment only with credit card. Order now.


This is the CB2318 Air Fuel Ratio Indicator.

The CB2318 is a bit simpler than AF30. More suitable for standard cars.

Price CB2318 with non heated oxygen sensor: 1995 Sek (about £153 ) including VAT and freight inside EU (European Union). Outside EU 1596 Sek. Note that if you live outside EU, local taxes and duties will be added when arriving to your country! Payment with credit card. Order now.


Air/Fuel Ratio Meter Operation.

An oxygen sensor, located in the exhaust passage, produces a signal that is read by the A/F Meter. The oxygen sensor must be hot, over 315 degrees before it will send a signal that the A/F Meter will respond to. You will normally experience a delay in the function of the A/F Meter until the exhaust system warms to operating temperature.

Oxygen Sensors

Engines that are equipped with fuel injection have oxygen sensors mounted in the exhaust system. The majority of oxygen sensors are equipped with only one wire. The wire is connected to the ECM. The A/F Meter feed wire can be connected to this wire. When properly connected, the A/F Meter will not effect the operation of the ECM. Some oxygen sensors have two wires. In this situation, one acts as a ground circuit. Do not connect the A/F Meter to the ground wire. One other type of oxygen sensor has three wires. This is a preheated type of oxygen sensor. It functions quicker than a single wire type due to the pre-heat function. One wire, (usually white) feeds infomnation to the ECM. The other two wires are used to provide 12 volts and a ground for the heater element built inside the oxygen sensor. Make certain not to connect the 12 volt heater wire or the ground wire to the ECM or A/F Meter circuit. A multi-meter can be used to determine the function of each wire. Engines that are not already equipped with an oxygen sensor must have an 18mm threaded adapter welded into the exhaust system. The oxygen sensor can then be screwed into the threaded adapter. The optimum location will allow the oxygen sensor to monitor all of the exhaust ports thereby providing complete A/F infommation to the A/F Meter.

Air/Fuel Ratios

The ideal A/F ratio when using gasoline is 14.7:1. This is expressed in pounds weight of air and fuel. An A/F ratio of 14.7:1 states that the engine is using 14 pounds of air for every pound of fuel. The optimal A/F ratio of 14.7:1 is referred to as Stoichiometric. ( This is shown as yellow lamps lights up on a Halmeter ) The goal is to approach and maintain stoichiometric or 14.7:1 A/F fuel ratio during idle and highway driving speeds. This is seIdom attained by carbureted engines.

The A/F ratio should richen to 13.1:1 or even less during acceleration and top speed. ( This is shown as green lamps lights up on a Halmeter ) The richer mixture is required during this time to aid in cooling the engine and to provide for increased power output. This is very important, specially on turbo charged engines. Deceleration will show leaner A/F numbers such as 16.1:1 as the throttles close and the engine burns off all available fuel. ( This makes the red lamps to light up on a Halmeter ) Attempting to run excessively lean A/F ratios can severely reduce engine life.
High engine temperatues, backfire through the carburetor, surging at highway speeds, and hesitation just off idle are indications of lean A/F ratios, and will show clearly on the A/F Meter.
Sluggish performance,black smoke,and poor economy are indications of a rich A/F ratio. This will also show on an A/F Meter.
More info below about the Halmeter

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Med denna mätare kan du själv ställa in din förgasare eller insprutning perfekt på alla varvtal både för ekonomi, normal och maxeffekt. Mäter avgasernas syreinnehåll, ungefär samma princip som en lambdasond för avgasrening. 30 lysdioder. 10 röda, 10 gula och 10 gröna. Ju längre åt höger lysdioderna lyser, desto fetare blandning. Förvärmd lambdasond. Kan monteras fast i bilen om man kör oblyad bensin. Kör man blyat används den bara vid test. Otroligt lätt att använda. Ingenting för den som gillar att tillbringa hela sin fritid på att försöka ställa in förgasarna genom att titta i avgasröret och på stiften.

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