A variety of counters and appliances that let realize detection of the elements let create many combinations of measurement systems with different level of complexity.

•  the maximal measurement scope
• a measurement accuracy
• a measurement resolution
• a possibilty of buildin-up sensors
• a kind of measured product an so on
• maksymalnego zakresu pomiarowego

The most simple system for units counting is the system, that bases on the proximity sensor that is connected wit the counter. Depending on material, that the elements are made of, their colour, transparent properties, size and conditions of the surrounding, matching sensor that assures appropriate detection, is chosen .

Electronic counters enable introducion of rate (multiplier or divisor) that can help by measuring (for example when the sensor is mounted axially, one laying bearing will be deteced two times).

Depending on the structure of the system for quantity measurement, mechanical stroke caunters (1 stroke = 1 piece) and mechanical turn counters (1 turn = 1 piece) can be applied.

 The length measurements can be realized based on electronic, electromechanical and mechanical counters.

Mechanical counters with measuring wheel are the most simple system for length measurement. Mechanical counters are proggresive-reversion counters.

While choosing the measuring wheel and the counter, following parameters should be taken into account:

• the diameter of the measuring wheel hole must fit diameter of the counter axis
  
• the perimeter of the wheel 20cm or 50 cm must fit counter ratio 1:2 (for 50 cm) or 1:5 (for 20 cm)
  
• the covering of the measuring wheel must be chosen appropriately to the kind of measured material
  
• the counter must have well-chosen direction of the turn, so that the gauge isn't upsied-down after setting up
  
• maximal rotating speed of the counter

By using the proximity sensors, elements on the winding beams or on propeller shafts can be detected. If we are able to specify stedy quantity for example of the tooth on the tooth-wheel or insets on the propeller shaft for specified lenght, than we can connect the proximity sensors with electomechanical or electronic counters. Such measuring systems are able to count only proggresively or only reversionaly.

Electronic counters with quadrature input are able to cooperate with turning – impulse converters (encoders). An encoder can be placed on the axis of the propeller shaft or a measuring wheel (appropriately done) can be placed on the axis of the encoder. Such a system assures the best resolution and measureemnt accuracy.

•  maximal input frequency of the counter > maximal speed of encoders axis turns [turn/s] * impulsation of the encoder [imp/turn]
  
• a measuring wheel that is placed on the axis of the encoder should work on the plain surface (it shouldn't bring vibrations and side-loads on the axis of the encoder)
  
• a shaft, taht the encoder is built on shouldn't bring any vibrations and side-loads on the axis of the encoder
  
• clutches are recommended for connecting mechanical turn elements with axis of the encoder