{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "instrument-mounts",
 "name": "Instrumentation: DS18B20 and K-type probes, hall sensor, encoder disc, dial-indicator stems",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Generators & instruments",
 "year": null,
 "question": "What are DS18B20 waterproof probe and K-type thermocouple probe dimensions?",
 "tags": [
  "sensor",
  "thermocouple",
  "ds18b20",
  "hall",
  "encoder",
  "dial indicator",
  "instrument",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "ds18b20 probe dimensions",
  "k type thermocouple probe diameter",
  "hall sensor mount 3d print",
  "encoder disc stl",
  "dial indicator stem diameter",
  "rpm sensor stirling engine",
  "thermocouple clamp"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 7,
 "url": "https://xemstudio.com/objects/instrument-mounts/",
 "sheet_txt": "https://xemstudio.com/objects/instrument-mounts/sheet.txt",
 "sheet": {
  "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",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "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."
  ],
  "table": {
   "columns": [
    "sensor",
    "size_mm",
    "range",
    "mount"
   ],
   "rows": [
    [
     "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"
    ]
   ]
  }
 },
 "sheet_text": "Instrumentation: DS18B20 and K-type probes, hall sensor, encoder disc, dial-indicator stems — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/instrument-mounts/  (CC BY 4.0)\nBasis: 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\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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.\n- 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.\n- 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.\n- 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.\n\nsensor  size_mm  range  mount\nDS18B20 probe  Ø6 × 50  −55–125 °C  clamp Ø6.15\nK-type sheathed  Ø3 or Ø4.8 × 100  to 1100 °C  clamp Ø3.15 / Ø4.95\nK-type bead  0.3–1 mm wire  to 1000 °C  mica washer\nhall A3144 / SS49E  TO-92 4.2 × 1.6 × 5  —  printed mount\nIR slot sensor TCST2103  3.1 mm gap  —  encoder disc Ø60\ndial indicator  Ø8 / Ø9.53 stem  10 mm travel  clamp Ø8.15 / Ø9.7\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Thermocouple — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Thermocouple\n- Wikipedia: Hall effect sensor — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Hall_effect_sensor\n- Wikipedia: Dial indicator — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Dial_indicator\n- Analog Devices: DS18B20 datasheet — PDF — Manufacturer datasheet — https://www.analog.com/en/products/ds18b20.html\n- Long Earth Society: Engine and rig builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 7 parts): https://xemstudio.com/files/hardware/instrument-mounts/index.json\nAPI: https://xemstudio.com/api/geometry?object=instrument-mounts\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Thermocouple",
   "url": "https://en.wikipedia.org/wiki/Thermocouple",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Hall effect sensor",
   "url": "https://en.wikipedia.org/wiki/Hall_effect_sensor",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Dial indicator",
   "url": "https://en.wikipedia.org/wiki/Dial_indicator",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Analog Devices",
   "title": "DS18B20 datasheet",
   "url": "https://www.analog.com/en/products/ds18b20.html",
   "formats": [
    "PDF"
   ],
   "license": "Manufacturer datasheet",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine and rig builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
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  "tolerance_mm": null
 },
 "related": [
  "axial-flux-generator-kit",
  "thermoelectric-tec1",
  "adafruit-stemma-qt-breakouts",
  "neodymium-disc-magnets",
  "tri-clamp-ferrule"
 ],
 "faq": [
  {
   "q": "What are the dimensions of a DS18B20 waterproof probe?",
   "a": "Ø6 mm stainless sleeve, 50 mm long (a 30 mm version exists), with a 1 m cable; it reads to 125 °C, so it belongs on the cold side."
  },
  {
   "q": "What diameter are K-type thermocouple probes?",
   "a": "Sheathed probes are Ø3 mm or Ø4.8 mm (3/16 in) by 100–150 mm; bare-bead types are just 0.3–1 mm wire and go anywhere up to 1000 °C."
  },
  {
   "q": "How do I measure the RPM of a Stirling engine?",
   "a": "A hall sensor 1–2 mm from a magnet on the flywheel (one pulse per magnet), or a slotted disc through an IR slot sensor; count pulses per second × 60 / pulses per rev."
  }
 ],
 "files_license": null,
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   "stl": "https://xemstudio.com/files/hardware/instrument-mounts/probe-clamp-ds18b20-6mm.stl",
   "note": "split clamp for a Ø6.0 probe/stem (ds18b20 6mm), M3 pinch"
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   "stl": "https://xemstudio.com/files/hardware/instrument-mounts/probe-clamp-k-type-3mm.stl",
   "note": "split clamp for a Ø3.0 probe/stem (k type 3mm), M3 pinch"
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   "note": "split clamp for a Ø4.8 probe/stem (k type 4 8mm), M3 pinch"
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  {
   "file": "probe-clamp-dial-indicator-8mm",
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   "note": "split clamp for a Ø8.0 probe/stem (dial indicator 8mm), M3 pinch"
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   "note": "split clamp for a Ø9.53 probe/stem (dial indicator 3 8in), M3 pinch"
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  {
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   "stl": "https://xemstudio.com/files/hardware/instrument-mounts/hall-sensor-mount-to92.stl",
   "note": "TO-92 hall sensor mount (A3144 / SS49E), M3 foot"
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  {
   "file": "encoder-disc-30-slots-60mm",
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   "note": "optical encoder disc Ø60 × 1.5, 30 slots, Ø5.2 bore (for an IR slot sensor)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/instrument-mounts/index.md"
}