question: How do vehicles detect how far you can go on your current amount of gas? Wouldn’t sensors not work due to the gas sloshing around?
comment: Average gas mileage is built in. Cars estimate the remaining mileage based on how much gas is left. Yes, the gas sloshes around a bit, but while the car is in constant motion, the gas doesn’t move a lot. It moves around mostly when braking or accelerating.
passages: "Note: Carburetors are largely dependent on air volume flow and vacuum, and neither directly infers mass. Consequently, carburetors are precise, but not accurate fuel metering devices. Carburetors were replaced by more accurate fuel metering methods, such as fuel injection in combination with an air mass flow sensor (MAF)."
  
  Section::::EGR testing.
   Section::::Remote readouts.
  
  Remote reading is becoming popular for gas meters. It is often done through an electronic pulse output mounted on the meter. There are different styles available but most common is a contact closure switch.
  
  Section::::Flow measurement calculations.
   if the pressure at inlet or outlet changes (even if the change is small), and when a batch changes, or when multiple products are in the pipeline. Gas pipelines are almost always in transient conditions, because gases are very compressible. Even in liquid pipelines, transient effects cannot be disregarded most of the time. LDS should allow for detection of leaks for both conditions to provide leak detection during the entire operating time of the pipeline.
  
  Section::::Internally based LDS.
   Flow metering accuracy is easily compromised if there are liquids in the gas stream. Therefore methods are implemented to remove liquids from the gas stream before measurement. However a newer V-Cone technology (the inverse of orifice plate technology) is being used to more accurately meter gas that contains some liquids.
  
  Section::::See also.
  
  BULLET::::- AGA-8
  
  BULLET::::- AGA-3
  
  BULLET::::- American Gas Association
  
  BULLET::::- Landfill gas monitoring
  
  BULLET::::- NX-19
  
  Section::::External links.
  
  BULLET::::- http://www.sgc-valid8.com -- Free online Flow Measurement Calculation and Verification Engine
   BULLET::::- Carbon dioxide emitted is theoretically directly proportional to the fuel consumed at a given and constant air fuel ratio. Less carbon dioxide will be emitted per litre of fuel if λ  1, since some fuel won't be able to combust completely.
  
  Section::::Types of sensors.
  
  Section::::Types of sensors.:Chemical CO sensors.
   In many late model automobiles, a Mass Airflow (MAF) sensor is used to accurately determine the mass flowrate of intake air used in the internal combustion engine. Many such mass flow sensors use a heated element and a downstream temperature sensor to indicate the air flowrate. Other sensors use a spring-loaded vane. In either case, the vehicle's electronic control unit interprets the sensor signals as a real time indication of an engine's fuel requirement.
  
  Section::::Vortex flow meters.
   Engine vacuum is the difference between the pressures in the intake manifold and ambient atmospheric pressure. Engine vacuum is a "gauge" pressure, since gauges by nature measure a pressure difference, not an absolute pressure. The engine fundamentally responds to air mass, not vacuum, and absolute pressure is necessary to calculate mass. The mass of air entering the engine is directly proportional to the air density, which is proportional to the absolute pressure, and inversely proportional to the absolute temperature.
   Section::::Automotive applications.: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 output voltage of the sensor.
  
  Section::::Automotive applications.:Sensor failures.
   Some technicians will force the engine to run lean by creating a vacuum leak downstream from the mass airflow sensor, and then watch scanner PIDs for a response. The engine can be forced rich by adding a metered amount of propane to the incoming airflow. In either case, if the sensor does not respond, it likely has a problem. However, these tests do not rule out other circuitry problems or ECM issues. Thorough, systematic diagnosis is recommended.
  
  Section::::Sensor types.:Comparison with mass airflow sensor.:Operating temperature.
   According to the API document "RP 1130", LDS are divided into internally based LDS and externally based LDS. Internally based systems use field instrumentation (for example flow, pressure or fluid temperature sensors) to monitor internal pipeline parameters. Externally based systems use a different set of field instrumentation (for example infrared radiometers or thermal cameras, vapor sensors, acoustic microphones or fiber-optic cables) to monitor external pipeline parameters.
  
  Section::::Rules and regulations.
  
  Some countries formally regulate pipeline operation.
  
  Section::::Rules and regulations.:API RP 1130 "Computational Pipeline Monitoring for Liquids" (US).
   Section::::Externally based LDS.
  
  Externally based systems use local, dedicated sensors. Such LDS are highly sensitive and accurate, but system cost and complexity of installation are usually very high; applications are therefore limited to special high-risk areas, e.g. near rivers or nature-protection areas.
  
  Section::::Externally based LDS.:Analytic thermal leak detector for above ground pipelines.
   With OBD II standards, vehicle manufacturers were required to test the exhaust gas recirculation (EGR) valve for functionality during driving. Some manufacturers use the MaP sensor to accomplish this. In these vehicles, they have a MAF sensor for their primary load sensor. The MaP sensor is then used for rationality checks and to test the EGR valve. The way they do this is during a deceleration of the vehicle when there is low absolute pressure in the intake manifold (i.e., a high vacuum present in the intake manifold relative to the outside air) the powertrain control module (PCM) will open the EGR valve and then monitor the MaP sensor's values. If the EGR is functioning properly, the manifold absolute pressure will increase as exhaust gases enter.
   Custody transfer requires an entire metering system that is designed and engineered for the application, not just flowmeters. Components of a custody transfer system typically include: 
  
  BULLET::::- Multiple meters/meter runs;
  
  BULLET::::- Flow computers;
  
  BULLET::::- Quality systems (gas chromatographs to measure energy content of natural gas and sampling systems for liquid);
  
  BULLET::::- Calibration using in-place or mobile provers for liquid, or master-meter for liquid or gas; and
  
  BULLET::::- Supporting automation.
   Section::::Externally based LDS.:Infrared radiometric pipeline testing.
   Internally based systems use field instrumentation (e.g. for flow, pressure and fluid temperature) to monitor internal pipeline parameters which are used to detect possible leaks. System cost and complexity of internally based LDS are moderate because they use existing field instrumentation. This kind of LDS is used for standard safety requirements.
  
  Section::::Internally based LDS.:Pressure/flow monitoring.
   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.
  
  Section::::Automotive applications.:The probe.
   The gauge sender is usually a magnetically coupled arrangement, with a float arm inside the tank rotating a magnet, which rotates an external gauge. The external gauge is usually readable directly, and most also incorporate an electronic sender to operate a fuel gauge on the dashboard.
  
  Section::::System components.:Valves.
   A leak-down tester is essentially a miniature flow meter similar in concept to an air flow bench. The measuring element is the restriction orifice and the leakage in the engine is compared to the flow of this orifice. There will be a pressure drop across the orifice and another across any points of leakage in the engine. Since the meter and engine are connected in series, the flow is the same across both. (For example: If the meter was unconnected so that all the air escapes then the reading would be 0, or 100% leakage. Conversely, if there is no leakage there will be no pressure drop across either the orifice or the leak, giving a reading of 100, or 0% leakage).
   In most modern installations, an electronic device called a "tachometric relay" or "safety switch" is used to operate electrical shut-off solenoids. These work by sensing that the engine is running by detecting ignition pulses. Some systems use an engine oil pressure sensor instead. In all installations, there is a filterlock (consisting of a filter assembly and a vacuum or electric solenoid operated shut-off valve) located at the input to the converter. In "European" converters, there is also a solenoid in the converter to shut off the idle circuit. These valves are usually both connected to the output of the tachometric relay or oil pressure switch. Where solenoids are fitted to the outputs of fuel tanks, these are also connected to the output of the tachometric relay or oil pressure switch. In installations with multiple tanks, a switch or "changeover" relay may be fitted to allow the driver to select which tank to use fuel from. On bi-fuel, the switch used to change between fuels is used to turn off the tachometric relay.
   Section::::Gas content control methods.
  
  Gas content control is essential for equipment which can be negatively influenced by gas content in the oil (such as power transformers) . Gas content can be measured by devices which measure the changing residual pressure in an oil sample container. 
  
  Such tests offer quantitative indications of gas content, but no qualitative analysis.
   In the development process of internal combustion engines with engine test stands, an air flow meter or air flow measuring unit is used for measuring the continuous gravimetric air consumption of combustion engines.
  
  Section::::In automobiles.:Industrial environments.
  
  Air flow meters monitor air (compressed, forced, or ambient) in many manufacturing processes.
   On some vehicles only three LF transmitters are used in order to save money. The vehicle assumes that transmissions from a nearby TPM which has not been woken up by the LF belong to the TPM located where there is no LF transmitter.
  
  High line systems are inherently more expensive than low line systems but they have the advantage of the vehicle knowing the pressure when started without draining the vehicle's main battery and providing localisation. These systems tend to be used on higher end models.
  
  Section::::Direct tire pressure monitoring systems.:Low line system.
   Fluids stored in tanks are a principal object of constant commercial telemetry. This typically includes monitoring of tank farms in gasoline refineries and chemical plants -- and distributed or remote tanks, which must be replenished when empty (as with gas station storage tanks, home heating oil tanks, or ag-chemical tanks at farms), or emptied when full (as with production from oil wells, accumulated waste products, and newly produced fluids). Telemetry is used to communicate the variable measurements of flow and tank level sensors detecting fluid movements and/or volumes by pneumatic, hydrostatic, or differential pressure; tank-confined ultrasonic, radar or Doppler effect echoes; or mechanical or magnetic sensors.
   Section::::Mechanical flow meters.:Gear meter.
  
  Gear meters differ from oval gear meters in that the measurement chambers are made up of the gaps between the teeth of the gears. These openings divide up the fluid stream and as the gears rotate away from the inlet port, the meter's inner wall closes off the chamber to hold the fixed amount of fluid. The outlet port is located in the area where the gears are coming back together. The fluid is forced out of the meter as the gear teeth mesh and reduce the available pockets to nearly zero volume.
   Gas meters are required to register the volume of gas consumed within an acceptable degree of accuracy. Any significant error in the registered volume can represent a loss to the gas supplier, or the consumer being overbilled. The accuracy is generally laid down in statute for the location in which the meter is installed. Statutory provisions should also specify a procedure to be followed should the accuracy be disputed.
  
presuppositions: Gas sloshes around during driving. Gas is always sloshing around in the gas tank.
corrections: Gas does not move a lot while the car is in constant motion. Gas doesn't move a lot when the car is in constant motion.
raw_presuppositions: Gas sloshes around during driving. Gas is always sloshing around in the gas tank.
raw_corrections: Gas does not move a lot while the car is in constant motion. Gas doesn't move a lot when the car is in constant motion.