kVp Meter and Exposure Timer

kVp Meter and Exposure Timer


The “kVp Meter & Exposure Timer” provides a convenient and fast method of measuring the effective kilo Peak Voltage (kVp) and exposure time of Diagnostic X-ray machine. These are important parameters of quality of Diagnostic X-ray machines among the others like Focal Spot size, tube screen alignment, operating mAS etc.

A non-invasive method, wherein the ratio of response of X-ray detectors located under filters of different thickness is correlated for the measurement of kVp. The instrument meets the quality assurance requirements of both dental and Diagnostic X-ray machines.


The instrument consists of a Readout Unit and a Detector unit which are interfaced using RS-232 communication. Detector Unit and Reader units are based on low power microcontroller Atmel 89C8252. The instrument uses three semiconductor diode detectors under filters of varying thickness to cover a wide range of kVp measurement from 50 kVp to 120 kVp. One of the detectors is used to measure the exposure time. The instrument has features of automatic reset before new measurement, distance independent operation between Detector unit and X-ray target, measurement of kVp and exposure time in a single exposure and user friendly 16 digits, two line alphanumeric LC display. The instrument is calibrated in standard X-ray machines, which are in turn calibrated with a standard potential divider method.


  • Voltage
: 50 kVp to 125 kVp (with accuracy of ± 3 kVp)
  • Time
: 10 mSec to 9999 mSec (with accuracy of ± 5 mSec)

Detector Unit
  • Power supply 
: 6V Re-chargeable battery pack
  • Dimensions 
: 200mm L X 130mm W X 70mm H
  • Weight
: 300gm (Approximately)

Reader Unit
  • Display 
: 16 Digit Two line Alphanumeric LC display
  • Power Supply
: 1.5V*4 Pencil cells (6V)
  • Dimensions
: 200L X 100mm W X 50mm H
  • Weight 
: 40gm (Approximately)


This instrument is an important tool for the Quality Assurance of medical diagnostic X-ray machines. At present no indigenous instrument of such type is available in India. To reduce the radiation exposure to the public by ensuring quality radiographs without retakes. The instrument meets the quality assurance requirements of both dental and Diagnostic X-ray machines.


  • Space : Any standard working place of 250 to 400 square Feet area for electronic laboratory is adequate.

  • Electronic assembly facility : Set of standard tools including soldering station and Universal device programmer for EPROM/Flash ROM programming

  • For Testing : Test and measuring instruments for voltage, current like Digital Multimeter, Oscilloscope 

  • For calibration of the instrument : Availability of Diagnostic X-ray machine.


  • Man power : One experienced Electronics Engineer and one assistant / Technician required for production, testing and calibration of the instrument.

For details contact :

    Head, Technology Transfer & Collaboration Division,
    TROMBAY, MUMBAI - 400 085
    Fax : 091-022-25505151
    Email : technology@barc.gov.in