9
2 Description
2.1 Theory of Operation
The integrated flow monitor of the Loctite controller in connection with the Preamplifier
97211 measures the dispense pressure characteristic by means of a pressure sensor
and stores this parameter. The pressure sensor is integrated in the dispensing valve.
The measuring time corresponds with the dispense time sequence. The controller
compares the measured pressure characteristic with a previously stored reference
characteristic, based on four different criteria:
– Dispensing time
– Integral of pressure characteristic; corresponds with quantity of product dispensed
– Length of envelope curve for pressure characteristic
– Center of gravity
If the measured values are within the pre-set tolerance zone, this dispensing cycle is
recognized as o. k. and the ready signal will be available. If the deviation is outside the
tolerance zone, this dispensing cycle is detected as an error, and a fault is signaled.
This message is indicated on the display at the controller. It is also provided as a signal
at the socket XS 5 of the Automatic Controller 97123 or at the socket XS 9 of the Dual
Channel Automatic Controller 97103. This signal has to be acknowledged.
Integral
p
Gesamtdosierzeit
Total Dispensing Time t
Hüllkurve
Envelope Curve
Flächenschwerpunkt
Center of Gravity
1. Triggerpunkt
1
st
Triggerpoint
2. Triggerpunkt
2
nd
Triggerpoint
Normaler Druckverlauf mit einem Dosierventil
Typical Pressure Characteristic with a Dispensing Valve