RTD Series 21
Complete family of full range 1/4" diameter probes including hermetic designs. Every platinum element type in wire or thin film, single or dual is available.

21A –	Straight probe
21C –	Hermetically sealed rigid probe with 1/2 NPT hex mount and connector
21H –	Hermetically sealed straight probe with transition and cable
21B –	Rigid probe with welded double 1/2 NPT hex mount
21D –	Spring-loaded probe with universal spring inside any style pipe mount

RTD Series 218
Full range 1/8" diameter probes respond faster.
Small diameter suits lab use.

218A –	Straight probe
218T –	Straight probe with 1/4" diameter transition to larger leads

RTD Series 22
FM approved for explosion proof use with all element and hardware styles. Probe sheaths in either stainless steel or Inconel are approved.

22B –	Rigid probe with welded double 1/2 NPT hex mount
22D –	Spring-loaded probe with universal spring inside any stainless steel mount

RTD Pressure Fail-Safe
Exclusive seal at mounting withstands 1500 PSI if probe tube is severed. Recommended for pipeline or any applications specifying a back-up seal.

22314 –	Rigid probe, welded header inside welded double 1/2 NPT mount
22421 –	Spring-loaded probe, welded header above spring in the mount

RTD Series 23
Optimized mid-range thin film RTDs with fast response, immersible design. Low cost 1/4" diameter probes highlight low-cost spring-loaded mount choices.

23A –	Straight Probe (Can be cut or bent).
23B –	Rigid Probe with welded double 1/2 NPT hex mount.
23D –	Spring-Loaded probe with universal spring inside
	any style 1/2" Pipe Mount.