Ashcroft CI Series Bimetal Thermometer

Fits local mechanical temperature indication where you need a tamper-resistant (no external adjustment) 304 SS hermetically sealed bimetal dial thermometer rated for continuous service to 800 °F (425 °C) and intermittent to 1000 °F (500 °C) — no electrical output.

Key advantages

Grade A accuracy — ±1% of span per ASME B40.200 (B40.3 Grade A).
Tamper-resistant case — no external adjustment; hermetically sealed construction.
Wide service band — continuous service to 800 °F (425 °C); intermittent to 1000 °F (500 °C).
NEMA 4X / IP66 — sealed construction for washdown and outdoor indication.

Typical applications

Process lines that need a sealed dial thermometer without field recalibration screws.
OEM equipment panels specifying CI-series bimetal indication.
Utility and HVAC piping where mechanical local readout is enough.

Selection guide

Sensor — Bimetal coil; Maxivision dial 2″ / 3″ / 5″.
Range — Standard dial ranges through family tables; continuous service to 800 °F (425 °C); intermittent to 1000 °F (500 °C). JSON range span example −100…1000 °F.
Accuracy — ±1% of span ASME B40.200 (B40.3 Grade A).
Output — Mechanical dial indication (no electrical output).
Process connection — Plain, pointed stem, ¼ NPT, ½ NPT (2″ uses ¼ NPT fixed).
Stem — Diameter 0.250″ or 0.375″; length 2½″ to 24″ (longer on request).
Case / stem — 304 SS case & stem (hermetically sealed); tamper-resistant case (no external adjustment).
Ingress — NEMA 4X / IP66.

Common mistakes

Expecting external dial recalibration — CI is tamper-resistant with no external adjustment.
Running continuous service above 800 °F — intermittent allowance to 1000 °F is not continuous duty.
Skipping a thermowell above 15 psi process pressure.
Ordering 2″ dial with the wrong connection — 2″ uses ¼ NPT fixed.
Specifying an electrical output — this SKU is mechanical dial only.
Ignoring silicone-dampened coil when vibration would otherwise blur the pointer.

When to RFQ / what to tell us

Dial size (2″ / 3″ / 5″) and dial temperature range from the family tables.
Stem diameter (0.250″ / 0.375″) and stem length; connection (plain / pointed / ¼ NPT / ½ NPT).
Mount orientation (rear / lower) and whether a thermowell is required (>15 psi recommended).
Silicone-damped coil yes/no; quantity; ship-to country.

Request a Quote · Get selection help

Specs

Spec	Value
SKU	39219
Brand	Ashcroft
Model	CI Series
Product type	gauge (bimetal thermometer)
Measuring range	Standard dial ranges; continuous to 800 °F (425 °C); intermittent to 1000 °F (500 °C)
Sensor type	Bimetal coil
Accuracy	±1% of span ASME B40.200 (B40.3 Grade A)
Output	Mechanical dial indication (no electrical output)
Process connection	Plain, pointed stem, ¼ NPT, ½ NPT (2″ uses ¼ NPT fixed)
Stem diameter	0.250″ or 0.375″
Stem length	2½″ to 24″ (longer on request)
Sheath / case	304 SS case & stem, hermetically sealed, tamper-resistant
IP / NEMA	NEMA 4X / IP66
Response	Improved with silicone-dampened coil option
Ambient (dry)	−40…+200 °F (−40…+93 °C)
Display	Maxivision dial 2″ / 3″ / 5″
Head / mount	2″ rear; 3″/5″ lower or rear; direct stem; thermowell recommended >15 psi
Approvals	RoHS
Notes	Specs from Ashcroft CIbimetaldsRevH03-03-25. Tamper-resistant (no external adjustment).

Documents

Ashcroft CI Series datasheet (PDF)

FAQ

Q: Can I recalibrate the CI Series externally? A: No. The case is tamper-resistant with no external adjustment per OEM published values notes in our JSON.

Q: What accuracy and temperature limits apply? A: ±1% of span (ASME B40.3 Grade A). Continuous service to 800 °F (425 °C); intermittent to 1000 °F (500 °C).

Q: Does it have an electrical output? A: No — mechanical dial indication only.

Q: What should I send for a quote? A: Dial size/range, stem Ø/length, connection, orientation, dampening, thermowell need, quantity, ship-to. Available for systems that use Ashcroft CI Series — we do not claim authorized-dealer status.