Results obtained with the first four gap MWPC prototype chamber

Results of measurements made with a full size four gap multi-wire proportional chamber prototype for the inner part of the LHCb muon system are presented. Special emphasis has been placed on the comparisons between the calculated and measured detector capacitances of the wire and cathode pads. The efficiency and cross talk in the case of a combined anode-cathode readout of the prototype were measured in a test beam. In general the properties of the chamber are well understood, although the cause of instability in the front end electronics needs to be resolved. With the possible exception of cross talk between anode wire pads the prototype fulfils the requirements for the LHCb muon system. Further studies with this prototype are planned and will update these results.