Tecfluid AMO For 2000 Series - Manual (Page 2)

1. OPERATION
The AMO is an optical flow rate detector. It is used with variable area flowmeters that employ
transparent flow metering tubes and transparent liquids. The AMO detects the presence of the float
and its direction of displacement, so it can act as a maximum or minimum flow switch. The detector
state is maintained until the float passes in the opposite direction at the limit switch position,
switching to its previous state.
2. INSTALLATION INSTRUCTIONS
2.1 Installing the detector
A range of different detectors are available to adapt to the different types and sizes of metering
tubes. The physical form of the detectors may vary, but their operation is identical.
The detectors are fixed to the flowmeter chassis by means of screws located at the ends of the
arms.
2.2 Type of alarm
The detectors have two sensing elements mounted in one of the arms and an infrared emitter
mounted in the opposite arm. When the detector is mounted as shown above with the two
sensing elements to the (Pos.1), the relay of the flow switch is activated when the float rises and
is deactivated when the float falls. In this position the AMO can be used as a maximum alarm
and is deactivated in absence of the power supply, or it can be used as a minimum alarm that is
activated in absence of the power supply. If the detector position is changed placing the sensing
elements at the right (Pos.2), the systems logic in inverted.
Float Position Pos.1 Pos.2 Relay
Flow rate < Set Point X Deactivated
Flow rate < Set Point X Activated
Flow rate > Set Point X Activated
Flow rate > Set Point X Deactivated
The following precautions must be taken when using an AMO:
- Sunlight and light from incandescent bulbs can affect the operation of the system. The
detector must be mounted in a position where direct light does not fall on the sensing
elements.
- Transparent or red translucent floats are not recommended since the infrared light can go
through them and the sensor elements may not be activated.
- The liquids should be transparent and clean.
2
Activate
Deactivate