Design and implementation of SMT-Based electronic pen pocket dosimeter with built in battery charger

As all portable instruments are battery operated and has strictly limited power so a power conscious design for such instruments is essential. In this paper the design and implementation of SMT-based electronic pen pocket dosimeter (PD V2.1) is presented. The overall power consumption is significantly reduced (<24 m W) by smart software and hardware design to allow longer time intervals between recharging. This pocket dosimeter, which is a GM-based, is used to measure personal accumulated quantities of gamma rays and the strength of a radiation field. The design of the PD V2.1 is based on the PIC16F876 micro controller and powered from two AAA size,250 mAh rechargeable batteries. This pocket dosimeter is compact, lightweight and a fully automated equipment of high quality. Its surface mount technology (SMT) meets the requirements for small size and high reliability. An integrated serial interface allows easy connection with any personal computer. A powerful graphical User interface software (GUI) has been developed for easy displaying and of radiation readings over any time period. The integrated alphanumerical liquid crystal display (LCD) displays not only the accumulated dose and current dose rate, but also alarm messages such as low battery. For reasons of power saving the LCD is activated on demand by pressing the push button or automatically when an alarm occurs. Audible and visual alarms have been added in order that they cannot be accidentally overlooked or ignored