Patent ID: 7111503

Claim:
A probe for analyzing fluid concentrations in a fluid to be analyzed, the probe comprising: a probe body; a sheet-form membrane secured to the probe body and including end and side perimeter edges, an outer facing side exposed at least in part to the exterior of the probe, an inner facing side opposite the outer facing side and a total membrane surface area measured on one of the inner facing side or the outer facing side between the end and side perimeter edges; a channel formed between the probe body and the membrane through which a collector fluid can flow; an inlet port opening to the channel to conduct collector fluid to the channel; and an outlet port spaced from the inlet port such that the collector fluid passes through the channel from the inlet port to the outlet port in a flow direction substantially parallel to the membrane; the channel being defined by a depth between the probe body and the membrane and a width extending substantially orthogonal to the flow direction between side limits of the channel and the width being at least 5 times greater than the depth; and the total membrane surface area includes an active area that is open both (i) on the outer facing side to the fluid to be analyzed and (ii) on the inner facing side for contact with collector fluid flow in the channel and the active area is at least 20% of the total membrane surface area.