Philips FM-2, Service Manual

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Measurements Channels
10 Chapter 1 - General Information
Measurements Channels
Ultrasound Channel
The monitor has two ultrasound sockets, US 1 and US 2, located on the side
panel of the monitor. Either one or two M1356A ultrasound transducers can be
connected. The latter case allows twins monitoring. (Refer to the
Instructions for
Use
for transducer specifications).
The transmitter pulsing the ultrasound transducer is gated by control circuitry,
and return signals are processed in the CODEC circuitry on the main board.
Toco Channel
The Toco circuit uses a Wheatstone bridge, with two strain gauge elements
mounted on a load beam. The differential output voltage is proportional to the
force applied to the load beam through the plunger. The Toco circuit is powered
from a single regulated 5V-supply excitation.
The amplified and filtered TOCO signal is converted by a 12-bit analog to
digital converter, providing an output scale of 2.56LSBs/gram.
Mountings
The monitor can be mounted in two ways using the following optional items:
• GCX roll stand (M3909A)
• GCX wall-mount (M3904A)
Refer to the fitting instructions that come with the relevant option.