Just to ensure we're all on the same page, the poster appears to be looking to replace JUST the two-wire temperature sensor that came with a commercial CampChef unit, not the sensing and display electronics as well. So a replacement probe has to match both the mechanical interface, which is probably 1/8 phone plug, now usually called 3.5mm, but also the electrical interface. These are probably Pt
RTDs, but the bridge and power supply are part of the display package (ie separate from the probe) that is read on the pellet unit itself, and this feature may be of value to the poster. If the probe resistance and bias current design isn't exactly what the CampChef original used, it probably won't work right. If it's approximately close, some units allow you to balance the bridge (by calibrating at easy to create standards at 32F and 212F) but I'm not seeing that in
the manual.
I overlooked that in my earlier post because I'm an Old Nut who never uses the factory probes or iPhone interfaces and I just use cheap (and plenteous!) probe/display packages like the Ikea. (In fact I keep the factory probe connections plugged with rubber plugs at all times to keep weather and critters out.) But a lot of folks want their meat probes to be compatible with their expensive cooker itself, if only because they don't want their guests to see something looking like a science experiment with wires and gauges galore strung all over. So matching the RTD electronically will be important to them.
Another subtle point is that these cookers have a near-permanently-mounted temp probe in the cook chamber that is used by the PID or other controller to reach and maintain setpoint. It's safe to assume CampChef uses a similar RTD and wire insulation on this probe.
So even if, like me, one is willing to ignore the factory meat probes in favor of a "better" standalone probe/bridge/display package, that factory chamber probe will be subject to the same concerns.
I'll bet this is bigger than CampChef and is one of these unintended consequences of "market development". These pellet cookers started as basic ease-of-use smokers and chamber temperatures in excess of 325F was just not part of their feature list. So I suspect there could be other designs based on using silicone insulation on the probe wires and thereby have ~350F limitations whether it's admitted or not. And now that the feature set includes things like slots in heat diffusers to permit "grilling" temperatures, that limitation becomes important! And analogous units like Weber SmokeFire and
Masterbuilt Gravity Feed are now marketed touting even higher cooking temperatures. I gotta' wonder what they're using for RTD wiring insulation!
Caveat emptor would sure seem to apply here. Before plunking down big bucks on a cooker, it's worth checking into what the sensors are, and the details of their wiring...many cookers are approaching mica or fiberglass insulation realms but may be using something less. I think the original poster has done us all a favor.