Taxi Meters

​In 2015 APLMF agreed to summarise the test procedures used in each APLMF training course and then to survey its members to validate the test procedures and to provide some quality control. The validated test procedures will be later used to develop eLearning modules. 

The summary test procedures are provided to guide economies wishing to follow OIML recommendations. They contain abbreviated terms and formulae which are defined in the relevant OIML recommendation.

Information relating to taxi meters:
SUMMARY OF TEST PROCEDURES USED TO VERIFY TAXI METERS
  • These test procedures are based on OIML R21.
​Test Name
​Procedures Description
Distance measurement transducer​
  • Check the distance measurement transducer.
  • The transducer should convert a rotation signal to an electrical signal efficiently.
Display screen
 
  • Check the display screen.
  • Each screen should display the current status luminously and clearly.
Tires of driving wheels
​Check tires of driving wheels:
  1. Tires should be dry and clean.
  2. Tyre pressure measurement value should be a rated pressure specified by the manufacturer. 
  3. Write down the pressure value of tires.
Load
  • ​During the verification procedures, the load of the vehicle should equal the weight of two adults, which ranges from 120 to 180 kg.
Calculate the tire correction value
​​For new type taxi, the value of the tyre correction error should be determined as follows before using error test: 
  1. Along a straight and flat road, draw two parallel lines tread-width apart, then mark the taxi start position across the width of the tyre-with a long line
  2. Mark the start position on each side of the driving wheels. 
  3. Start the car slowly, and mark the end lines on the road after driving wheels rotate through five cycles. 
  4. Measure the distance travelled by each wheel after five cycles, B1, B2 and record the average value B  from formula \[B=\frac{B_{1}+B_{2}}{2}\], as the distance taxi traveled after five cycles on a road, using the unit of meter.
  5. Drive taxi onto the reference taximeter using error standard device of  taximeter calibration, rotate driving wheels on both sides five cycles moving forward, then record the distance from the calibration instruments travelled by each side A1, A2 and get  the average value A from formula \[A=\frac{A_{1}+A_{2}}{2}\] as the calibrated value of  distance taxi traveled after five cycles, using the unit of meter.
  6. Calculate the tire correction value C using the formula  \[C=(\frac{A}{B}-1)x100\%\]
Calculate the using error
​​Select at least three test points including the starting distance and two increase distance points.
  1. Direct the taxi to the standard device along the guide line with the driving wheels of taxi fixed between the main roller and vice roller. 
  2. Sit next to the driver, turn off the engine, set to "neutral" and release the brake. 
     - For front wheel drive cars the "handbrake" is in the on position,
     - For rear wheel drive cars the "handbrake" is released.
  3. Turn the meter on to show the taximeter is in hired mode.
  4. Observe distance-counting screen of the taximeter, when the distance-counting value reaches the first test point, press “sample” key on the remote control, and record the value.
  5. Calculate using errors according to the formula as follows:
    \[D_w=\frac{Dx(1+C)-J_d}{J_d}x100\%\] ​
    where: 
    Dw -  the using error，%；
    D -  distance-counting value of taximeter, using the unit of meter；
    C - the tyre correction value, %；
    Jd - distance counting value of taximeter using error standard device, unit, using the unit of meter.
  6. If the using error is within +1.0% ～ -4.0%, then the taximeter has passed, can be sealed and a “qualified ID” sticker can be placed in a prominent position.
SUMMARY OF ECONOMY REPORTS
This report is unavailable for taxi meters. 
SURVEY RESULTS ON ADOPTING THE TAXI METER TEST PROCEDURES
Test name
Total economies surveyed
Adopted
Not implemented
Economies not responded
​1. Environmental condition
19
11
1
7
​2. Reference samples
19
12
7
​3. Visual and electrical inspections
19
12
1
7
​4. Measurement of errors 
19
11
1
7
​Economies responded
Cambodia, Canada, Hong Kong China, Indonesia, Japan, Malaysia, Mongolia, New Zealand, Papua New Guinea,  Chinese Taipei, Thailand, Vietnam

Economies not responded
Australia, China, DPR of Korea, Republic of Korea, Philippines, Singapore, United States of America