Fluke Biomedical 4000M+ - Manual (Page 14)

Victoreen 4000M+
Operators Manual
2-6
NOTE
When the unit is upside down in the Fluoroscopic
Mode, the display automatically inverts so it can be
read from that position.
Ion Chamber Signal Connector
The Ion Chamber Signal Connector, labeled SIGNAL, is a BNC connector that accepts the input and
signal from the external ion chamber.
CAUTION
An electrical shock hazard exists on the ion
chamber bias (HV). Extreme care should be taken
when in close proximity to the ion chamber bias.
Ion Chamber Bias Connector
The Ion Chamber Bias Connector, labeled BIAS, is a banana-type jack supplying 300 DC volts as bias
supply for an external ion chamber.
RS-232 Port
The RS-232 Port is a 9-pin female connector configured as Data Communications Equipment (DCE).
See Appendix B for more information on this port.
2.5 Detector Positioning
The detector must be positioned according to the type of measurement required. Section 3 – Theory of
Operation includes a detailed discussion of detector positioning.
The following guidelines outline general detector positioning principles:
1. Locate the detector 46 to 102 centimeters (18 to 40 inches) away from the source of x-rays.
NOTE
The optimum source-to-detector distance (SDD) is
66 centimeters (26 inches) for most measurements.
Refer to Appendix A for a discussion of source-to-
detector distance.
2. The black plastic disk (on the top panel of the Model 4000M+) must point toward the source, and
must be in the approximate center of the beam.
3. The beam must be parallel to, and in the same direction as, the BEAM DIRECTION arrow printed
on the rear panel of the Model 4000M+.
4. To eliminate measurement error due to the ‘heel’ effect, position the Model 4000M+ so that the
front-to-rear panel axis is parallel to the tube axis.