DIGITAL INSTRUMENT READING RECOGNITION

An algorithm for recognizing digits from an image of a device with a digital indication as a tool of an automated workplace of a metrologist is considered.

A Rugged Semiautomatic Extensometer for Rubber

The evaluation of an elastomer—new or established—inevitably involves a study of tensile properties. ASTM procedure D 412 is generally used as a guide for the tensile testing of vulcanized rubber. In this method, an operator observes bench marks on the sample and records the modulus at every 100% elongation, the ultimate elongation, and the tensile strength at break. An extensometer has been developed to eliminate operator coordination and judgment factors from rubber tensile testing. It is simple and sufficiently rugged for routine testing. Its features are a counterbalanced guide rod with a sliding electrical contactor, and specimen followers which automatically unlatch to avoid being damaged when specimens break. In addition there is a counter for direct digital indication of elongation, and an electrical circuit which controls a short duration spark to mark the autographic chart. Experience in testing up to 5000 specimens per year has shown that the apparatus makes an inexperienced operator as effective as trained operators working under optimum conditions. The instrument has been used successfully on materials ranging from soft rubber to plasticized and filled poly (vinyl chloride).