Loma IQ2 Service Manual page 37

"Configuration menu". The values range from 150 KΩ up to 1.5MΩ. The
detector will not allow a speed to be entered that is outside the range allowed by
the selected filter resistor value. Driven systems generally are detectors which
are mounted on conveyor systems, however if the product is pumped and the
speed at which it is pumped is known e.g. a Pipeline detector mounted after a
Vacuum Filler, then a fixed speed can be entered.
The other option available "Frun" which is primarily used for gravity fed product
i.e. "Freefall" or "Pharmaceutical" type systems or when a pump speed is not
known. However there is still a maximum speed through the aperture, which if
exceeded will reduce the detector performance. When this option is used two
further filter resistor values will appear in the menu, 68 and 120 KΩ, these
values allow faster speeds.
For example:
The smallest aperture dimension of my detector is 150 mm (6" rounded) and my
conveyor speed is 50 m/min (164 fpm rounded). Therefore according to the
table following I can use either 150, 180, 220 or 330 KΩ resistor packs. A
suggested rule of thumb is to select the value whose range sets the speed
required roughly central.
The resistor pack is factory set according to the specified speed. However if the
speed of the conveyor is altered from the original then the value and menu entry
should be checked to ensure it is still allowable with the existing filter resistors. If
the value is to be changed then the recommended resistor type is
Metal film at 1% tolerance
The following pages detail the range of resistors available and the speed ranges
allowed for fixed, variable and freerun systems.
The resistors are located on a removable plastic 8-pin header plug on the main
control board. Refer to the
for the location of the resistor pack in the maintenance section of this
page 6
manual. The "Configuration" menu contains a position called "Filter resist" where
the value of the resistors fitted is entered. The entered value must match the
fitted value.
Module 7026
Configuration and Set up Information
Control/PSU Board component layout Figure 2
on
5-15