Instrumentation: DS18B20 and K-type probes, hall sensor, encoder disc, dial-indicator stems — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/instrument-mounts/  (CC BY 4.0)
Basis: Common probe sizes: DS18B20 stainless sleeve Ø6 × 50 (some Ø6 × 30), K-type sheathed probes Ø3 / Ø4.8 (3/16 in), bead thermocouples 0.3–1 mm wire; dial indicators Ø8 mm (metric) / Ø9.53 (3/8 in) stems; TO-92 hall sensors
Catalog version: 2026-10-20

Sizes: see table below
- DS18B20 waterproof: Ø6 × 50 mm stainless sleeve, 1 m cable, −55 to 125 °C (so the cold side only). K-type: bare bead (0.3–1 mm wire) to 1000 °C for the hot end; sheathed Ø3 × 100 or Ø4.8 × 100 with a mini-K plug; MAX6675/MAX31855 boards read them. Mount probes in a split clamp (Ø + 0.15, M3 pinch) and leave 10 mm of sheath in the gas path.
- RPM: TO-92 hall sensor (A3144 digital, SS49E analogue) in the printed mount 1–2 mm from a passing magnet; or the Ø60 slotted encoder disc through an IR slot sensor (TCST2103, 3 mm gap): 30 slots → 30 pulses/rev.
- Dial indicator stems: Ø8 mm (metric) or Ø9.53 (3/8 in, US); the clamps here hold them for measuring displacer travel and flywheel runout. Stroke of a Stirling displacer: measure at the rod with the engine turned by hand.
- LES: hot-end K-type under the ferrule clamp, DS18B20 on the cold spool, hall sensor at the flywheel rim, dial indicator on the displacer rod during commissioning.

sensor  size_mm  range  mount
DS18B20 probe  Ø6 × 50  −55–125 °C  clamp Ø6.15
K-type sheathed  Ø3 or Ø4.8 × 100  to 1100 °C  clamp Ø3.15 / Ø4.95
K-type bead  0.3–1 mm wire  to 1000 °C  mica washer
hall A3144 / SS49E  TO-92 4.2 × 1.6 × 5  —  printed mount
IR slot sensor TCST2103  3.1 mm gap  —  encoder disc Ø60
dial indicator  Ø8 / Ø9.53 stem  10 mm travel  clamp Ø8.15 / Ø9.7

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Thermocouple — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Thermocouple
- Wikipedia: Hall effect sensor — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Hall_effect_sensor
- Wikipedia: Dial indicator — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Dial_indicator
- Analog Devices: DS18B20 datasheet — PDF — Manufacturer datasheet — https://www.analog.com/en/products/ds18b20.html
- Long Earth Society: Engine and rig builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 7 parts): https://xemstudio.com/files/hardware/instrument-mounts/index.json
API: https://xemstudio.com/api/geometry?object=instrument-mounts