Welch Allyn LC101 CO2 Module - User Manual - Manual (Page 13)

LC101 CO
2
Module OEM Implementation Manual Section 1 - Functional Description
Welch Allyn OEM Technologies Confidential Page 13
Sidestream Components
The functional components necessary for sidestream operation include
• pump
• watertrap and watertrap receiver assembly
• inlet and exhaust tubing
• CO
2
sample line
• cannula
The flow control circuitry regulates flow by using a fixed orifice flow sensor that provides
feedback to a circuit that controls power to the pump. A differential pressure transducer
measures the pressure drop across a restrictor and this is used as feedback to adjust the pump
speed. The pump power supply steps down the raw voltage applied to the board to a level
appropriate for maintaining the desired pump flow rate.
The pump connector provides the electrical connection for the pump to the Main Board.
The watertrap receiver assembly connector provides the electrical connection for the
watertrap switch to the Main Board.
Pump
The electrically driven miniature oil-free diaphragm pump is mounted on the Main Board. The
pump draws the sample through the sample line to the sample chamber by creating a vacuum.
Fault states such as exhaust and watertrap occlusions are recognized by the flow control
circuitry. Refer to Section 5, Pneumatic Operation, for additional information on pump function.
Watertrap and Watertrap Receiver Assembly
NOTE The watertrap, watertrap receiver and receiver switch are not included with the LC101
Module and each may be ordered separately from Welch Allyn OEM Technologies or
supplied by the OEM.
The watertrap is a user-supplied cartridge that removes excess moisture in the sample line
before the sample is delivered to the sample chamber. The watertrap includes a built-in shutoff
pellet which is designed to fully occlude once the filter is saturated.
The functional components of the watertrap assembly include the watertrap receiver and
receiver switch.
The watertrap receiver is a receptacle for the watertrap and can be molded by the OEM into the
main housing of the host monitor (or purchased from Welch Allyn OEM Technologies as an
accessory). The external end of the watertrap is connected to the sample line.
The watertrap receiver switch provides a signal that is used for detection of a properly inserted
watertrap into the watertrap receiver before the pump begins operation. This eliminates the
possibility of the user bypassing the watertrap.