Research And Development Of Electronic Thermometer Batch Automatic Verification Device

With the implementation of the Minamata Convention,the markets of electronic thermometers have been further expanded,and the automation production capacity has been increasing.However,thermometers need to be verificated on a case-by-case basis to meet the requirements of the national medical measuring instruments.The verification conditions include stable temperature field of the thermostat,accurate standard verification device,sufficient heat balance time,and the CCD image processing should be accurate and fast.The verification process includes start-up,buzzer and display,and seven types of rework path selection.To this end,the tooth-shaped chain plate conveyor is utilized in this thesis.The first batch automatic verification device is made according to the integrated requirements of starting buzzer display,temperature point verification and result classification.On this basis,a batch automatic verification device with independent operation of the three-function module is designed,which has utilized the flat top chain conveyor.The main work and achievements are as follows:(1)According to the verification requirements of 11,000 sets of single shifts,a batch automatic verification mechanical device which utilizes double conveying lines to share a single thermostat was proposed and developed.This device utilizes toothed chain conveyor,and the two conveying lines are mirror symmetrical.It can realize mechanical transmission and positioning of electronic thermometer start-up,buzzer detection,operation of thermostat inlet and outlet,indication detection and verification results sorting.Through the customization,processing,acceptance,assembly and actual debugging of various components,the mechanical transmission function of the electronic thermometer batch verification is realized.(2)The S7-200 PLC is utilized as the main controller.Through the programming of each function module,the communication function debugging and coordinated controlling,the device can realize the basic beat that finishing the verification of one thermometer per 3.5-5 seconds.After being putting on shelves,the electronic thermometers go through starting,buzzing and display performance test,entering the thermostat one by one,reaching the CCD image recognition position after specified balance time,and the image of the electronic thermometer display screen is obtained by using image processing technology.After obtaining the indication value by image processing,host computer compares this value with the standard temperature,and then,automatic sort the thermometer according to verification results.(3)Through the experimental tests which uses manual continuous racking at the inlet and sorting according to verification results at the outlet,it is verified that the automatic verification device can realize batch automatic verification of the electronic thermometer.However,it is found that if there is a problem with the function of a subsequent module in the verification process,it will cause accumulation in the front stage,which may affect the safety and reliability of the device.To this end,the core function of the indication temperature verification is separated from the startup buzzer module and the multi-channel sorting module.The second type electronic thermometer temperature display batch automatic verification device is designed which utilizes flat-top chain conveyor.After installation and initial commissioning,the second type device can initially realize the batch automatic verification of temperature indication of electronic thermometer.But the problem about integration of the front and rear devices needs to be solved.