Thermal & fluid
Temperature, ΔP, level and concentration across air, chilled-water, refrigerant and dielectric immersion loops.
Market
Data Center
As compute density rises, sensor instrumentation is critical for liquid cooling, immersion cooling and ambient environmental control in data centers.
Data center sensor portfolio
Sensing across every loop of the data center.
Amphenol Sensors is a Bronze Member of the Open Compute Project (OCP), the industry body defining open standards for data center hardware — from rack and power architecture to cooling environments and telemetry.
Air quality & humidity
RH, CO₂, air velocity and dew-point for DCV, condensation risk, and harsh-environment monitoring.
Power & current
Busbar hot-spot IR, ring-terminal NTC, Hall-effect current, PTC inrush protection from PDU to BESS.
Safety & leak
H₂, LEL, A2L and point/rope leak detection — with functional-safety options for BESS & UPS.
Step 1 — Choose a sub-system
Where in the data center are you sensing?
Click any tile to filter the portfolio to that loop.
7 sub-systems
Why it matters
AI racks have outgrown air.
GPU racks now draw more power than air can remove, so heat is carried away by liquid — through CDUs, manifolds and cold plates sitting millimetres from the chips. That brings coolant into the white space. A blocked cold plate, a failing pump or a slow drip can take compute offline fast, so every loop needs to be watched.
See the full Liquid Cooling page →Sub-systemLiquid Cooling
Measurand
35 of 35
Not sure what you need? Tell us about your liquid cooling application and our team will recommend the right sensors.
i2s
Quick-disconnect coolant pressure sensor with I²C output for rack and blade level
Applications
- Detection of leaks, blockages and flow interruptions in liquid-cooling loops at rack and blade level
- Tool-free installation and service via dry connect/disconnect port
- Ranges
- 0–7 bar up to 0–20 bar (35 bar overpressure)
- Accuracy
- ±0.5% FS (0–85 °C)
- Output
- I²C · 2.7–5.5 VDC
- Connection
- MQD-02 dry connect/disconnect · 4-pin JST
i2s
Stainless-steel coolant pressure sensor for rack inlet/outlet monitoring
Applications
- CDU and rack-manifold coolant pressure at rack inlet and outlet to assess cooling performance and protect server blades
- Ranges
- 0–7 bar up to 0–20 bar
- Accuracy
- ±1% FS (10–80 °C)
- Output
- 10–90% Vs ratiometric · 5 V supply
- Connection
- UNF 7/16"–20, HEX 24 · 3-pin plug
Telaire
Wet/wet differential pressure transmitter
Applications
- CDU loop ΔP across cold plates (flow-blockage detection)
- Pump ΔP for wear and cavitation trending
- Strainer / coolant-filter ΔP monitoring
- Type
- Wet/wet differential
- Media
- Glycol, water, oil (316 SS wetted)
- Output
- 4–20 mA
Custom variant
Glycol-compatible wetted materials (EPDM seals) as standard; optional NPT and G-thread process connections; extended-range version to 300 psid for primary-loop headers.
NovaSensor
NovaSensor NPI/IPT Harsh-Media Family
Applications
- CDU coolant-loop pressure (primary and secondary)
- Glycol fill / leak-down monitoring on closed loops
- Range
- 1 – 15,000 psi
- Output
- 4–20 mA, 0–5/10 V, I²C, SPI
- Accuracy
- ±0.25% FS
NovaSensor
Low-Cost Media-Compatible P+T
Applications
- CDU primary and secondary loop P+T
- Cold-plate inlet/outlet P+T (one device replaces two)
- Chilled-water and immersion-loop P+T
- CDU filter ΔP and pump-health ΔP
- Tech
- PT1907 MEMS die, no oil fill
- Range
- 15 – 600 psi
- Output
- I²C, SPI, 4–20 mA, Analog, SENT
Custom variant
LCMC is a platform, not a single SKU — specify range, interface (I²C / SPI / 4–20 mA / SENT), process connection and cable pigtail per CDU / compressor integration. No oil-fill keeps it glycol- and refrigerant-safe.
NovaSensor
Digital media-isolated pressure
Applications
- High-pressure coolant loops on CDU primary lines and immersion manifolds (digital I²C readout)
- Range
- 2.5 – 300 psi (A/G)
- Linearity
- ±0.25% FSO (BFSL)
- Interface
- I²C 14-bit
Custom variant
Optional Hastelloy C diaphragm for aggressive dielectric coolants and chemistries where 316L is attacked; custom process-port thread patterns on request for OEM CDU integration.
All Sensors
Stainless-steel piezoresistive — high media compatibility
Applications
- CDU primary-loop high-pressure media-compatible monitoring (G 1/8 in or weld-ring port; PG/EG and dielectric coolant compatible)
- Tech
- Piezoresistive (SS 316/316L wetted)
- Range
- 200 mbar – 35 bar (A / G / V)
- Output
- mV (1.5 mA constant-current)
All Sensors
Stainless-steel piezoresistive — analog + I²C
Applications
- CDU pressure monitoring with simultaneous I²C telemetry and analog control-loop output (SS-wetted, 13-bit resolution)
- Tech
- Piezoresistive + ASIC (SS 316/316L)
- Range
- 200 mbar – 35 bar / 3 – 500 psi
- Output
- 0.5–4.5 V ratiometric + I²C
Thermometrics
Waterproof IP68 overmolded NTC
Applications
- Immersion-rated coolant temperature on CDU and chilled-water loops (JIC stainless variant)
- Protection
- IP68 waterproof overmold
- Range
- −50 to +105 °C (+125 °C ≤ 6 h)
- Thermistor
- 10 kΩ NTC
Custom variant
Longer probe lengths (6″ / 12″) for duct insertion; threaded SS housing for pipe immersion; networked multi-probe cable (up to 8 probes / run) for rack-row monitoring.
Thermometrics
Screw-fixed surface NTC
Applications
- Ring-terminal-mount NTC on CDU pump cabinets and busbar lugs — coolant-line surface temperature where direct contact at a screw-terminal is needed
- Operating
- −40 to +125 °C
- R @ 25 °C
- 5K / 10K / 20K / 50K / 100K Ω
- Form factor
- Ring-terminal screw-mount
Thermometrics
Surface-stick NTC (flat / pipe / cable)
Applications
- Stick-on coolant-pipe skin temperature where retrofit on existing CDU lines is needed (no penetration)
- Operating
- −30 to +70 °C
- R @ 25 °C
- 9983 Ω (typ)
- Mounting
- Pressure-sensitive adhesive
Thermometrics
Inline NTC with barb fittings
Applications
- Chilled-water coil inlet/outlet temperature
- CDU coolant-loop inline temperature with barb fittings (no weld-in)
- Operating
- −40 to +120 °C
- R @ 25 °C
- 10 kΩ ±1.5%
- Interface
- SAE J-1231 / Triple-Barb
Thermometrics
Acid/moisture-resistant coated chip
Applications
- Coolant and immersion-fluid temperature in harsh environments (acid / moisture exposure)
- Direct-immersion temperature in two-phase / dielectric coolants where standard NTC encapsulants degrade
- Operating
- −40 °C to +190 °C
- Compliance
- AEC-Q200 Rev D · RoHS · REACH
- Features
- Shock-resistant · silver-migration resistant
Telaire
Dew-point / enthalpy / wet-bulb
Applications
- Outdoor CDUs where dew-point / wet-bulb matters for condensation control
- Extended-range ambient monitoring above standard RH/T limits
- Operating env
- −40 to +60 °C, 0–99% RH
- Output
- 4–20 mA, 0–5 V or 0–10 V
- Measurands
- Dew Pt · Enthalpy · Wet Bulb · Dry Bulb
Telaire
OEM board-level T+RH
Applications
- Liquid-cooled rack environmental monitoring — RH+T inside CDU enclosures and adjacent dry-rack air space for condensation-risk surveillance
- RH accuracy
- ±2.0% RH (20–80%)
- Temp accuracy
- ±0.5 °C (14-bit)
- Output
- I²C or PDM
Amphenol
Epoxy-hardened waterproof transmitter
Applications
- CDU condensation-risk monitoring at equipment drip points
- RH accuracy
- ±2% RH (30–95%) @ 25 °C
- Feature
- Withstands 100% saturation
- Output
- 4–20 mA, 0–5 V or 0–10 V
SGX Sensortech
3 × 3 mm digital gas sensor that detects propylene-glycol (PG25) vapor from coolant microleaks
Applications
- Glycol (PG25) vapor detection for coolant microleaks at CDU drip pans and inside cooling blades near quick-disconnects
- Works alongside liquid leak detection: one firmware setting flags sudden sprays (relative output) and slow leaks (absolute trend)
- Type
- Metal-oxide gas sensor · embedded AI algorithms
- Package
- 3.0 × 3.0 × 0.9 mm IP67 (0.7 mm standard) · 12-LGA
- Interface
- I²C · 1.7–3.6 V · down to 200 µW
- Operating
- −40 to +85 °C · 10-year lifetime
Thermometrics
LET-Basic / LET-Plus / LET-Elite alarm modules with sense cable
Applications
- CDU under-rack leak loops; primary/secondary loop leak containment
- Type
- Rope-style sense cable + alarm module
- Cable length
- Up to 500 m (Basic, Plus) · up to 1,500 m locating (Elite)
- Interface
- RS485 Modbus RTU · BACnet IP / Modbus TCP support · relay outputs
Thermometrics
Point/spot water-detection sensor
Applications
- CDU and primary-loop drip-tray water detection — dry-contact alarm back to leak-monitor or BMS
- Sensing R
- 510 kΩ ±3% (1/4 W)
- Supply
- 5 VDC recommended
- Operating
- −40 to +85 °C
Rochester
Capacitive liquid-level transmitter (with TLL head)
Applications
- CDU reservoir level (non-conductive coolants)
- Probes
- 500 / 1000 mm; field-cut to length
- Liquids
- Diesel, kerosene, non-conductive fluids
- Supply
- 9–36 VDC (80 V OVP, reverse-polarity)
- Output
- Resistive / 0–5 V / 4–20 mA (TLL head)
- Accuracy
- ±1% FS
- Cert.
- CE, RoHS; IP65 head
Rochester
Top-mount magnetic dial level gauge (mechanical)
Applications
- CDU glycol reservoir local readout
- Type
- Top-mount 5-bolt magnetic level gauge
- Accuracy
- ±6 % (6700 base), ±7 % (Adjustable)
- Variants
- 6741 / 6781 + TwinSite® sender
Rochester
Cellular radar tank monitor (remote telemetry)
Applications
- CDU reservoir / coolant tank fill-level tracking on remote / edge sites — cellular reporting without a DCIM integration
- Sensing
- Radar — non-invasive tank level
- Network
- CAT-M1 / NB-IoT cellular (FCC)
- Battery life
- Up to 10 years (ATEX logger)
- Certifications
- ATEX / IS; UL 913 Class I Div 1, Zone 0
Rochester
Guided-wave radar level transmitter
Applications
- Large-reservoir CDU / thermal-storage tank level where foam or vapor defeats ultrasonic
- Sensing
- Guided wave radar (TDR); no moving parts
- Range
- Up to 3 m; <2 mm resolution
- Output
- 0.5–4.5 V / 4–20 mA options
- Sealing
- IP6K9K
Rochester
Custom float and leak switches (point level)
Applications
- CDU reservoir hi/lo float alarm
- Point leak-switch under manifolds and CDUs
- Type
- Custom-engineered float & leak switches
- Capabilities
- Multi-level, side-mount, continuous, P+T combos
- Mfg.
- IATF 16949 — Coppell, TX
Custom variant
Built-to-order: specify stem length, float material, switch action (N.O./N.C.), process fitting, cable and connector. Rochester Quick-Turn (Coppell, TX) builds from the 9871 / 9872 / 9873 / 9875 families — IATF 16949 North-American manufacturing, OEM-volume capable.
SSI
Non-contact ultrasonic level
Applications
- Non-contact level in CDU reservoirs where immersion probes are unwanted
- Max depth
- 32" diesel / 24" gasoline
- Accuracy
- ±0.125"
- Outputs
- 3-wire resistive · voltage · DFT-110
SSI
T + Ultrasonic + Level + Concentration
Applications
- CDU glycol concentration monitoring — one device reports level, temperature and glycol concentration over a single interface
- Concentration
- 0–50%, ±3%, 0.25% res.
- Level
- 20–850 mm, ±3 mm
- Comm
- J1939 CAN
Wilcoxon
High-MTBF industrial accelerometer
Applications
- CDU pump-bearing vibration monitoring — early detection of impeller imbalance, cavitation and bearing wear before coolant-flow loss reaches the racks
- Sensitivity
- 100 mV/g ±5%
- Response
- 0.5 – 14,000 Hz
- Max temp
- 120 °C
- Compliance
- API 670; CSA / ATEX / IECEx variants
IMI
Echo® sensor + EchoPlus® wireless
Applications
- CDU-pump vibration trending without running conduit to the pump skid
- System
- Wireless sensor + EchoPlus® JB + Receiver
- Measures
- Peak/RMS vel, accel, crest factor
- Integration
- Modbus®
Piher
Flange-mount gear-tooth speed sensor
Applications
- CDU-pump RPM feedback for closed-loop flow control
- Supply
- 4–24 VDC (two-wire)
- Max speed
- 12 kHz fwd / 40 kHz (A/B)
- Operating
- −40 to +125 °C
Piher
Open-loop Hall-effect current sensor
Applications
- Open-loop current sensing on CDU pump and heater circuits (wire-through)
- Range
- ±25 A – ±1,000 A
- Output
- Ratiometric 0.5 – 4.5 V
- IP
- IP67 / IP69K
Custom variant
Split-core (clamp-on) retrofit variant for installation on live feeders without disconnecting wires; custom window geometry for non-standard busbar sections on request.
Piher
Non-contact Hall-effect rotary
Applications
- CDU valve-position feedback on motorized ball valves (non-contact, 50 M-cycle life)
- Linearity
- ±1% (±0.5% on request)
- Range
- Programmable 50°–360°
- Supply
- 5 V ±10% or 7–32 V
Thermometrics
Non-invasive pipe-skin NTC clips
Applications
- Non-invasive coolant-pipe temperature on CDU primary and secondary loops (no break-in retrofit)
- Chilled-water plant pipe-skin temperature trending across multiple pipe diameters
- Drop-in retrofit on existing whitewater and TCS lines without draining the loop
- Pipe OD range
- 8 – 54 mm (multiple clip sizes)
- Range
- −40 to +150 °C
- Mount
- Spring-clip, no break-in
Custom variant
Family covers OD 12.7 / 18 / 22 / 28 / 35 / 42 / 54 mm with single connector standard (M12 A-coded). Thermally-conductive non-marring TPE pad compatible with PG/EG and dielectric coolants.
Telaire
SIP through-hole T+RH module
Applications
- SIP through-hole T+RH integrated on CDU control PCBs and BMS boards for board-level condensation prevention
- RH accuracy
- ±2.0% RH (20–80%)
- Output
- I²C or PDM
- Package
- 4-pin SIP through-hole
Thermometrics
NTC probe — water-ingression resistant
Applications
- Outdoor CDU coolant lines exposed to weather, coastal / humid sites (UV + chloride + sulfate resistant per HACT testing)
- Type
- NTC thermistor probe; HACT-tested
- Resistance
- Standard NTC curves (5K / 10K / 50K Ω)
- Range
- −40 to +150 °C
Thermometrics
Coolant immersion probe — brass housing
Applications
- CDU coolant immersion temperature on water / glycol loops — brass-housing thread-in alternative to clip-on surface sensors when an immersion probe is preferred
- Type
- NTC immersion probe (brass)
- Resistance @ 25 °C
- 2129 Ω ± 4.87%
- Range
- −30 to +150 °C
The takeaway
From MEMS on the PCB to transducers on the pipe.
Purpose-mapped across CRAC/CRAH, CDU & immersion, PDU/UPS, rack infrastructure, server boards, standby generators and BESS — so the same supplier covers the entire data-center thermal, power and safety envelope.
Custom Variant options are available on many products: extended ranges, alternate housings, split-core retrofits, and certified industrial housings packaged around Amphenol sensing elements.
Disclaimer: All product specifications and descriptions are subject to change without notice. The information on this page is for general guidance only and does not constitute a warranty of any kind. To confirm current specifications and product suitability for your application, please contact Amphenol Sensors directly.