What pressure ranges are available for the PXT-K Series transmitter?

The PXT-K Series is available across a wide range of pressure ratings, from bi-directional low-pressure ranges of -30 in. H₂O to +30 in. H₂O and -30 in. Hg to +30 psig, through gauge pressure ranges of 0-15 psig up to 0-10,000 psig. This broad selection makes the PXT-K suitable for applications ranging from low-differential liquid level monitoring all the way to high-pressure hydraulic and wellhead systems.

What is the supply voltage required for the PXT-K Series?

The PXT-K Series operates from a supply voltage of 8 to 30 VDC, with 24 VDC being the typical operating voltage. The minimum supply voltage required at the transmitter depends on the total loop resistance — a Loop Resistance Graph is provided in the product documentation to determine the correct minimum voltage for any given load resistance value. For FW Murphy controller input modules such as the Centurion C4-1, MX5, and Centurion C5, minimum voltage requirements range from 13.00 to 13.98 VDC depending on the specific module's input impedance.

Is the PXT-K Series suitable for use in hazardous or classified locations?

Yes. The PXT-K Series holds ATEX certification (IBExU 10 ATEX 1124 X) for II 1G Ex ia IIC T6-T4 (Zone 0, intrinsically safe) and II 3G Ex nA IIC T6 (Zone 2, non-sparking), as well as CSA (c/us) certification for Class I/II/III, Division 1, Groups A-F T4 and Division 2, Groups A-D, F, G T4. These dual certifications make it suitable for use in North American and international hazardous area installations including oil and gas wellheads, offshore platforms, and chemical processing facilities.

What is the accuracy of the PXT-K Series pressure transmitter?

The PXT-K Series achieves ±0.25% of span accuracy (Best Fit Straight Line / BFSL) at 25°C. The temperature error band is ±2.5% of span over the full operating temperature range (-22 to 176°F / -30 to 80°C) and ±1.7% of span over the compensated temperature range (-20 to 160°F / -29 to 71°C). Response time is under 5 milliseconds, making it suitable for fast-changing pressure monitoring in dynamic process environments.

What electrical connection options are available for the PXT-K Series?

Two electrical connection options are available. The PXT-K model features a 1/2 NPT male conduit connection with a 60-inch vented cable using 28 AWG stranded wire — suitable for installations requiring conduit wiring. The PXT-KM model uses an M12 x 1 connector, with optional M12 cables available in lengths of 3, 6, 30, 50, and 100 feet for flexible wiring in the field.

What protection does the PXT-K Series offer against electrical faults and interference?

The PXT-K Series includes built-in protection against reverse polarity wiring and short circuit conditions, with a maximum wiring protection voltage of 48 VDC. It also provides voltage surge and spike protection rated for 600-volt spikes per IEC 60-2. The internal signal conditioning circuitry is specifically engineered for class-leading EMI/RFI resistance, meeting EMC standards EN 61000-6-2:2005, EN 61000-6-3:2007, and EN 61326-2-3:2006 — making it reliable in electrically noisy industrial environments.

PXT-K Series piezoresistive 4-20mA pressure transmitter with 316L stainless steel body and NEMA 4 IP65 enclosure for industrial compressor engine and process pressure measurement

PXT-K Series · Pressure Sensor

4-20 mA Two-Wire | 316L SS Body | ATEX & CSA Certified

Pressure Sensing · Industrial Transmitters · Hazardous Area Instrumentation

PXT-K Series – Piezoresistive 4-20 mA Pressure Transmitter for Industrial Applications

The PXT-K Series is a rugged, two-wire 4-20 mA piezoresistive pressure transmitter engineered for reliable pressure measurement in demanding industrial environments. Built with a 316L stainless steel body and all-stainless wetted parts, it delivers accurate, stable output across a wide range of pressures — from low-range liquid level monitoring to high-pressure compressor and process applications. Available with either a flying lead conduit connection (PXT-K) or an M12 connector (PXT-KM), and certified to ATEX and CSA hazardous area standards, the PXT-K Series is a proven choice for engineers specifying reliable pressure sensing on engines, compressors, pumps, and process systems.

±0.25% Accuracy (BFSL)

4-20mA Two-Wire Output

800g Shock Resistance

NEMA 4 IP65 Enclosure

Key Features

The PXT-K Series pressure transmitters are precision instruments designed for long-term reliability in the harshest industrial conditions. Each unit combines a piezoresistive silicon sensing chip, advanced internal signal conditioning electronics, and an all-316L stainless steel enclosure to deliver consistent 4-20 mA output with minimal temperature-induced error. Whether installed on a natural gas compressor, a diesel engine, a process skid, or a liquid level application, the PXT-K Series provides the measurement stability and electrical robustness that engineers and plant operators depend on for both monitoring and protective shutdown functions.

Piezoresistive Silicon Sensing Technology with Class-Leading EMI/RFI Resistance: At the heart of every PXT-K transmitter is a piezoresistive silicon chip mounted on a glass-metal feed-through header and hermetically sealed inside a silicone oil-filled stainless steel cell. A laser-welded stainless steel isolation diaphragm transfers process pressure through the oil to the silicon element, completely isolating the active chip from the process media. Combined with advanced internal signal conditioning circuitry, this design achieves extremely low temperature error and class-leading immunity to electromagnetic and radio-frequency interference — critical in environments near VFDs, generators, and high-voltage switchgear.
All 316L Stainless Steel Body and Wetted Parts: The transmitter body, enclosure, and every part that contacts the process medium are machined from 316L stainless steel. This grade of stainless offers superior resistance to chloride-induced corrosion, making the PXT-K suitable for saline, acidic, and chemically aggressive process fluids without requiring additional protective coatings or barriers. The consistent use of a single material throughout the wetted assembly also eliminates galvanic corrosion concerns at material interfaces.
Wide Pressure Range Coverage from Vacuum to 10,000 psig: The PXT-K Series is available across an exceptionally broad span of pressure ranges, from bi-directional low-pressure service (-30 in. H₂O to +30 in. H₂O) for draft and ventilation measurements, through standard gauge ranges from 0-15 psig to 0-600 psig for typical engine and pump service, up to high-pressure ranges of 0-3,000 psig to 0-10,000 psig for hydraulic systems and high-pressure injection applications. This range of options means a single transmitter platform can be standardized across multiple measurement points in a facility.
NEMA 4 / IP65 Enclosure with Shock and Vibration Resistance: The transmitter enclosure meets NEMA 4 and IP65 or better ratings, providing protection against rain, splashing water, windblown dust, and industrial wash-down cleaning. Shock resistance is rated at 800g per IEC 60068-2-27 and vibration resistance at 20G per IEC 60068-2-6, making the PXT-K suitable for direct mounting on reciprocating compressors, engines, and rotating machinery where vibration levels and mechanical shock events are routine. Mounting is supported in all axis positions with negligible effect on measurement performance.
ATEX and CSA Dual Hazardous Area Certification: The PXT-K Series carries ATEX certification (IBExU 10 ATEX 1124 X) for both Zone 0 intrinsically safe use (II 1G Ex ia IIC T6-T4) and Zone 2 non-sparking installations (II 3G Ex nA IIC T6), as well as CSA (c/us) certification for North American Class I/II/III, Division 1 (Groups A-F T4) and Division 2 (Groups A-D, F, G T4) classified locations. This dual certification simplifies global project specifications and ensures compliance on both ATEX-governed European projects and NEC-governed North American installations.
Reverse Polarity, Short Circuit, and Surge Protection: Built-in wiring protection covers reverse polarity connections and short circuit faults up to 48 VDC, guarding the transmitter electronics against damage during commissioning, maintenance wiring errors, or cable faults in the field. Voltage surge and spike protection is rated for 600-volt spikes per IEC 60-2, providing a critical buffer against transient events on long cable runs or in facilities with poor power quality. Insulation resistance is greater than 10 MΩ at 300 VDC.
Two Electrical Connection Options for Installation Flexibility: The PXT-K model offers a 1/2 NPT male conduit connection with a 60-inch vented flying lead cable (28 AWG stranded wire), while the PXT-KM model provides an M12 x 1 circular connector for tool-free, IP-rated field connections. M12 cables are available in standard lengths from 3 feet to 100 feet, allowing the PXT-KM to be installed and disconnected without disturbing the conduit wiring — a significant advantage for predictive maintenance programs requiring periodic transmitter removal and recalibration.

Applications

Compressor Lube Oil, Discharge, and Suction Pressure Monitoring: Reciprocating and screw compressors require continuous monitoring of lube oil pressure, stage suction pressures, and interstage and discharge pressures to maintain safe and efficient operation. The PXT-K Series provides stable, accurate 4-20 mA readings that feed compressor controllers, alarm annunciators, and safety shutdown systems, with the 800g shock and 20G vibration ratings ensuring measurement integrity even when mounted directly on compressor frames or discharge manifolds experiencing significant mechanical loading.
Engine Oil and Fuel Pressure Measurement: Diesel and gas engines in power generation, pumping, and compression service depend on reliable lube oil pressure and fuel supply pressure readings for both performance monitoring and protective shutdown functions. The PXT-K's broad pressure range selection covers typical engine lube oil pressures (0-100 to 0-200 psig) and fuel system pressures simultaneously, while the EMI/RFI resistance prevents measurement interference from the ignition systems, alternators, and variable frequency drives commonly associated with engine-driven equipment.
Industrial Process Control and SCADA Systems: Process plants handling liquids, gases, and steam require pressure transmitters with reliable 4-20 mA outputs that integrate cleanly into PLCs, DCS systems, and SCADA platforms. The PXT-K Series two-wire loop configuration simplifies field wiring — a single twisted pair carries both power and signal — and the transmitter's ±0.25% BFSL accuracy and sub-5 millisecond response time make it suitable for both steady-state monitoring and fast-acting pressure control loops on reactors, separators, heat exchangers, and pipeline systems.
Liquid Level Measurement by Hydrostatic Pressure: Tanks, vessels, and sumps can be monitored for liquid level by measuring the hydrostatic pressure at the bottom of the fluid column. The PXT-K's low-range options — including the 0-15 psig and 0-60 psig ranges — are well suited for level monitoring in water treatment, chemical storage, and fuel tank applications, while the NEMA 4/IP65 enclosure and all-stainless construction provide the weather and corrosion resistance needed for outdoor storage tanks and underground sump installations.
Pump Systems and Pipeline Pressure Monitoring: Centrifugal and positive displacement pump systems require suction and discharge pressure monitoring for both performance optimization and protection against deadheading, cavitation, and over-pressure events. The PXT-K's fast response time and accurate, drift-resistant output make it suitable for both the slow, steady monitoring of pump discharge headers and the faster pressure transient detection needed for pump protection in water injection, chemical dosing, and hydrocarbon transfer service.
Offshore and Hazardous Area Instrumentation: Offshore oil and gas platforms, onshore wellhead facilities, petrochemical plants, and gas processing sites require pressure transmitters certified for use in classified locations where flammable gases or combustible dusts may be present. The PXT-K's combined ATEX and CSA certification covers the full range of hazardous area classification systems used globally, while the all-stainless construction, NEMA 4/IP65 enclosure, and 316L wetted parts provide the corrosion and environmental protection demanded by offshore and coastal installations.

Technical Specifications

Specifications listed below apply to the PXT-K Series (flying lead connection) and PXT-KM Series (M12 connector) piezoresistive pressure transmitters.

Parameter	Specification
Sensing Technology	Piezoresistive silicon chip on glass-metal feed-through header; silicone oil-filled cell; laser-welded isolation diaphragm
Transmitter Output	4-20 mA, two-wire with load characteristics
Supply Voltage	8 to 30 VDC (typically 24 VDC)
Available Pressure Ranges	-30 in. H₂O to +30 in. H₂O · -30 in. Hg to +30 psig · -30 in. Hg to +100 psig · 0-15 · 0-60 · 0-100 · 0-200 · 0-300 · 0-400 · 0-600 · 0-1,000 · 0-2,000 · 0-3,000 · 0-5,000 · 0-6,000 · 0-10,000 psig
Accuracy (BFSL at 25°C)	±0.25% of span
Zero/Span Setting Tolerance	±2.5% of full scale max (30V30WC range only); ±0.25% of span typical / ±0.5% of span max (all other ranges)
Temperature Error Band — Operating	±2.5% of span over -22 to 176°F (-30 to 80°C)
Temperature Error Band — Compensated	±1.7% of span over -20 to 160°F (-29 to 71°C)
Response Time	<5 mS
Operating Temperature	-22 to 176°F (-30 to 80°C)
Compensated Temperature Range	-20 to 160°F (-29 to 71°C)
Body Material	316L Stainless Steel
Wetted Parts	316L Stainless Steel
Enclosure Rating	NEMA 4 / IP65 or better
Process Connection	1/4"-18 NPT female; 7/8" hex nut (2,000 psig and below) or 1-3/16" hex nut (3,000 psig and above)
Electrical Connection — PXT-K	1/2"-14 NPT male conduit connection; 60 in. vented cable; 28 AWG stranded wire
Electrical Connection — PXT-KM	M12 x 1 circular connector
Wire Colors	Red = 4-20 mA signal; Black = +Vdc / V-/SIG
Shock Resistance	800g per IEC 60068-2-27 (Mechanical Shock)
Vibration Resistance	20G per IEC 60068-2-6 (Vibration Under Resonance)
Mounting Position	All axis positions; negligible effect on performance when perpendicular to flow
Environmental Effect (Humidity)	No effect for 0–95%, non-condensing
Insulation Resistance	>10 MΩ at 300 VDC
Wiring Protection	Reverse polarity and short circuit protection; 48 VDC maximum
Voltage Surge / Spike Protection	600 V spike protection per IEC 60-2
EMC Standards	EN 61000-6-2:2005 · EN 61000-6-3:2007 · EN 61326-2-3:2006
Hazardous Area — ATEX	IBExU 10 ATEX 1124 X; II 1G Ex ia IIC T6-T4; II 3G Ex nA IIC T6
Hazardous Area — CSA (c/us)	Class I/II/III, Div 1, Groups A-F T4; Class I/II/III, Div 2, Groups A-D, F, G T4
Canadian Registration Number	OF15236.2 (all provinces and territories)
Overall Body Length	2.97 in. (75.4 mm)
Overall Length with Conduit Connection	8.0 in. (203.2 mm)
Cable Length (PXT-K)	63.0 in. (1,600 mm)
Shipping Weight	6.5 oz (packaged: 4-3/4 × 4-3/4 × 2-3/4 in. / 121 × 121 × 70 mm)

Technical FAQ

Common Questions Answered

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The PXT-K Series covers a wide span of pressure requirements, from bi-directional low-pressure ranges of -30 in. H₂O to +30 in. H₂O and -30 in. Hg to +30 psig, through standard gauge ranges from 0-15 psig up to 0-600 psig for typical engine and pump service, and on to high-pressure ranges up to 0-10,000 psig for hydraulic and wellhead applications. This broad selection allows a single transmitter platform to be standardized across multiple measurement points within a facility.

The PXT-K Series operates from 8 to 30 VDC, with 24 VDC being the standard operating voltage. The actual minimum voltage required at the transmitter terminals depends on the total loop resistance. A Loop Resistance Graph provided in the product documentation shows the minimum supply voltage for any given load resistance value. For FW Murphy controller input modules, minimum voltage requirements range from 13.00 VDC (Centurion C5 / MX5-R2) to 13.98 VDC for a typical third-party PLC input card.

Yes. The PXT-K Series holds ATEX certification (IBExU 10 ATEX 1124 X) covering Zone 0 intrinsically safe and Zone 2 non-sparking installations, as well as CSA (c/us) certification for Class I/II/III, Division 1 and Division 2 North American classified locations. These dual certifications make the PXT-K suitable for use in oil and gas wellhead facilities, offshore platforms, chemical processing plants, and any other site requiring compliance with ATEX or NEC hazardous area requirements.

At 25°C, the PXT-K Series achieves ±0.25% of span accuracy using the Best Fit Straight Line (BFSL) method. Over the full operating temperature range (-22 to 176°F), the temperature error band is ±2.5% of span. Over the narrower compensated temperature range (-20 to 160°F), the temperature error band improves to ±1.7% of span. Response time is under 5 milliseconds, making the transmitter suitable for dynamic pressure monitoring applications.

The PXT-K model uses a 1/2"-14 NPT male conduit connection with a 60-inch vented flying lead cable (28 AWG stranded wire), with the red wire carrying the 4-20 mA signal and the black wire carrying supply voltage and signal return. The PXT-KM model is fitted with an M12 x 1 circular connector for tool-free field connection. Pre-assembled M12 cables are available in lengths of 3, 6, 30, 50, and 100 feet for the PXT-KM, along with a 1/4" x 1/4" NPT 316 stainless adapter for process connection needs.

The PXT-K Series includes reverse polarity and short circuit protection rated to 48 VDC, preventing damage during incorrect wiring or cable faults. Voltage surge and spike protection covers events up to 600 volts per IEC 60-2. The internal signal conditioning circuitry is engineered for class-leading EMI/RFI resistance, meeting EN 61000-6-2 (industrial immunity), EN 61000-6-3 (residential emissions), and EN 61326-2-3 EMC standards — ensuring stable, noise-free output even when installed near generators, VFDs, and high-voltage electrical equipment.