history of ultrasound

{"cid":"91195939","title":"ZT-12-2 2MHz Ultrasonic Thickness Gauge Ultrasound Probe Black Color Cast Iron","imgUrl":"https:\/\/img.chinax.com\/nimg\/18\/1b\/29ecac274548dd0ec1525fc8a342-200x200-1.jpg","attrs":{"Price":"Negotiation","Brand Name":"TMTeck","Model Number":"ZT-12-2","Minimum Order Quantity":"1pc","Delivery Time":"3-5 work day","Certification":"CE","Place of Origin":"China","Payment Terms":"T\/T, Western Union,paypal","Supply Ability":"100PCS\/Two weeks","Packaging Details":"Carton 30*15*24cm 2.5kg","Name":"Ultrasonic Transducer Probe","Model":"ZT-12-2","Frequency":"2MHz","Contact Diameter":"17MM","Measurement Range":"4.0 to 508mm","Temperature Range":"-10 to 70\u2103"}}

{"cid":"91198506","title":"Standard Ultrasonic Plastic Welder for ABS PP PVC Plastic Welding","imgUrl":"https:\/\/img.chinax.com\/nimg\/d5\/bf\/8819d0deb152a0eaaa4083cb3354-200x200-1.jpg","attrs":{"Price":"Negotiation","Brand Name":"KnMTech","Model Number":"KM-ME2018","Minimum Order Quantity":"Negotiation","Delivery Time":"8 working days","Place of Origin":"China","Payment Terms":"L\/C, T\/T, Western Union, Paypal","Supply Ability":"500sets per month","Packaging Details":"wood carton","Product Name":"Ultrasonic Plastic Welding Machine","elding time":"0.1-9s adjustable","Working frequency":"15KHZ\/20KHZ","Power supply voltage":"220V\u00b1 10V 50-60HZ","Input current":"10A","Output power":"1500W\/2600W\/3200W\/4200W","Working stroke":"75cm","Welding material":"PP\/PVC\/PE or other plastic","Frequency":"15KHz\/20KHz"}}