The Quality Control System for Resistive Position Transducer' s Calibration

CUSTOMER

Opkon Optik Electronic Control Technic Company

GOAL

Opkon is a company which producing resistive position transducers for exportation does a sensitive calibration to the resistive sensing component during the production. Before the calibration sensitivity information (with a defined resolution) of the sensing element is needed. This information will be used in calibration operation afterwards.

DESIGN and TECHNOLOGY

Beacuse of the necessities like varius lineer ruler lenghts, high data acquisition speed, aquisition of the different type signals a flexiple and integrated PC based measurement system was designed. A multi usage data acquisition card was used to acquire voltage information on a defined frequency. This card acquires clock pulse position information of the encoders used in the system and the voltage information from the ruler. The Project software was developed on the LabVIEW 6i software platform.

SOLUTION

Voltage data with a defined resolution has to be acquired in order to do the calibration job. An encoder was used to do this. While voltage reader probe travels on the ruler, picked up position information from encoder and voltage value saved on each encoder's pulse. In this way we get voltage/position characteristic of linear ruler.

Sensitivity, lenght of linear ruler, diameter of encoder and ratio of reductor values can input to software. So encoder pulse interval calculated over thiz values. Encoder pulse interval value as a trigger pulse is used while picking up voltage values. All the values are written to an Excel File.

Measurement sensitivity must be 0.1%. For to reach this value we should pick up voltage values each 0.1 mm on 100cm ruler. We used to sampling value is 1000 for required sensitivity. Encoder frequence is 50 KHz.

In this project we gave a serial number for each linear ruler. So no need to control the linear ruler again for indexing.

Result

System realized succesfully with required sensitiveness.

Application Area

Linear ruler manufacturers.