If your probes don't seem to be Tek or related to engine analyzers, then also look at HP's foray into laser interferometer systems, which had some transducers for barometric pressure, temperature, and other physical stuff, to compensate for effects on the laser optics. HP also had some other pressure transducer stuff related to HPLC and GC in their analytical equipment lines, up to around 6,000 PSIG.
Ed
