Anyway, it worked, so I'll put the shielding back on and consider it a job well done!
Congratulations! You may now be prepared to verify and repeat an "experiment" I did in the mid-1970s to detect the presence of people (warm bodies) using a single uncooled pyroelectric detector, a simple two-bladed light chopper, and a pricey PAR lock-in amplifier. Piece of cake to do this today with
cheap PIR sensors, but "back in the day" it did require some expensive "test equipment," although the pyroelectric element was dirt-cheap by any standards.
Harshaw Chemicals gave me a free sample to "play" with. I set up on a bench in our electronics lab and pointed the detector element more or less toward a hallway door on the opposite side of the room, maybe fifty feet away, with the chopper blades right in front of the detector. No optics involved, no salt lenses, no plastic Fresnel lens like modern PIR sensors use. IIRC, the chopper interrupted incoming radiation at about thirty hertz or so (variable speed with a photocell interrupter to sync the lock-in), and the PAR integrating time was about one minute. Not exactly fast responding, but my experiment was just a "proof of concept" demonstration to show my boss that I understood how those new-fangled pyroelectric detectors worked. People were touting incredible D* (D star) sensitivity ratings for an infrared detector operating at room-temperature, potentially rivaling liquid nitrogen-cooled PbSnTe photoconductive detectors, the "gold standard" then for IR detectors. If that's all Greek to anyone,
here is a nice little explanation from Hamamatsu on how infrared detectors work.
Well, it was was all hoo-hoo and marketing for this new "solution" looking for a "problem" to solve. About that same time, the basic operating principle (a permanently polarized, stressed, dielectric causing differential charge separation) was also being used to make electret microphones. Many engineers working with high-impedance piezoelectric strain gauges and accelerometers were already familiar with triboelectric effects, because special graphite-impregnated shielded coaxial cable was necessary to avoid triboelectric voltages, created by relative motion between the inner coaxial conductor insulation and the outer copper braid, which would overwhelm data acquisition from the high-impedance sensors mounted on vibrating structures.. like an aircraft wing. It was a real PITA attaching that special coax to Microdot connectors while avoiding shorting out the connector by smearing the graphite in the wrong place. So most of us didn't get real excited by this "new" development of temperature-stressed and sound-wave stressed dielectric transducers. Just shows-to-go-ya how short-sighted I was. The idea of using
two identical pyroelectric detectors, with their outputs differential connected, and their active areas exposed to two slightly different fields-of-view (FOV), to detect motion was absolutely brilliant. Sure wish I had thought of it.
So after playing around with the Harshaw Chemicals pyroelectric device for a few days (weeks?) we finally got back to work trying to figure out how to build a laser weapon system to shoot down ICBMs during their re-entry to atmosphere phase. Well, not me, actually. I never did believe that would work, photons having practically zero momentum and easily reflected by mirrored surfaces, but I was happy to help the scientists build their experiments for dog and pony shows. That type of work was good for several more decades of funding, but I graduated in 1978 and went to work in a different field. AFAIK, the electromagnetic rail gun (which we were also trying to develop) eventually became a successful weapon, but I had no direct involvement with that either. <sigh> Us warmongers are having a tough time, what with peace and prosperity threatening to break out all over the world... good thing that I am finally "retired" from all that.