Fluke Biomedical 07-487 - Manual (Page 5)

1
General Information
Warnings
1-1
Section 1
General Information
1.1 Warnings
WARNING
When working with x-ray equipment, proper care
must be taken to prevent injury. Please review x-
ray machine manufacturer’s suggested precautions
when working with x-ray equipment circuitry.
CAUTION
Users of mAs meters must be aware of the
potential damage to the x-ray generators in the
case of improper connection or failure of any part of
the metering circuit. The mAs meter is intended for
use only by those skilled in the calibration and
repair of x-ray machines. The most common cause
of failure of the mAs meter is incorrect connection
to the x-ray generator, usually to the tube filament
circuit.
1.2 Introduction
The Model 07-487 is a digital mAs meter used to measure the product of tube current and exposure time
of x-ray generators. It has two ranges of sensitivity, 199.9 and 1999 mAs. It is connected in series with
the tube current ground return line of the high voltage transformer. A full-wave bridge feeds a five-ohm
load resistor so that the polarity of the input signal is not important. It should be used only by those
generators providing open and short circuit protection of the metering circuit and where the circuit
operates near ground potential. The mAs meter will not read proper values when connected to mA
calibration points used for amplifier or servo control of mA or any point other than the ground return of x-
ray tube current.
1.3 Assembly Description
The single circuit board fits into the two-part case. The rear of the case has a battery cover over the 9 V
battery. The rear of the case may be removed to access the two calibration potentiometers. Do not over
tighten the screws or the case may be damaged.