Humidity sensor with nasicon-based proton-conducting electrolyte

A galvanic cell humidity sensor comprising:

• a housing having first and second ends;
• a proton conducting solid electrolyte comprising a composite of HZr.sub.2 P.sub.3 O.sub.12 and ZrP.sub.2 O.sub.7 disposed at the first end of the housing, the solid electrolyte formed in the shape of a disk having opposing faces;
• support means disposed within the first end of the housing for supporting the solid electrolyte within the housing;
• electrodes disposed on the opposing faces of the electrolyte;
• leads attached to the electrodes, the leads extending through the second end of the housing;
• a signal processor for receiving the leads;
• a thermocouple positioned adjacent the housing, the thermocouple interconnected with the signal processor;
• heater means positioned adjacent the first end of the housing for heating the solid electrolyte;
• a sample gas conduit extending through the first end of the housing to the solid electrolyte for permitting a sample gas to be introduced within the housing;
• a reference gas conduit for introducing a reference gas within the housing;
• and
• an output meter for monitoring humidity.

A galvanic cell assembly for measuring humidity comprising:

• a housing;
• a proton conducting solid electrolyte comprising a composite of HZr.sub.2 P.sub.3 O.sub.12 and ZrP.sub.2 O.sub.7 disposed in the housing;
• a signal processor on the exterior of the housing;
• a pair of electrodes fixed to the solid electrolyte;
• a pair of leads extending from the electrodes to the signal processor;
• a reference gas chamber;
• and
• a sample gas chamber for introducing a sample gas into the housing;
• wherein the signal processor measures the difference in humidity of a sample gas and a reference gas.

A galvanic cell assembly for sensing humidity at high temperatures comprising:

• a housing comprising a tubing;
• a proton conducting solid electrolyte comprising a composite of HZr.sub.2 P.sub.3 O.sub.12 and ZrP.sub.2 O.sub.7 positioned within the housing;
• sealant means for holding the proton conducting solid electrolyte within the housing;
• first and second chambers formed at each side of the solid electrolyte within the housing;
• a reference gas introduced into the first chamber;
• a sample gas introduced into the second chamber;
• an electrode formed on each side of the proton conducting solid electrolyte;
• leads extending from the electrodes to the exterior of the housing;
• and
• a signal processor for receiving the leads and comparing humidity of a sample gas with a reference gas.