The KX series is an industrial pressure transmitter specifically certified for use in Zone 2 hazardous areas, employing non-sparking (Ex nA) and increased safety (Ex ec) protection modes. Built with thick film on stainless steel technology, these sensors feature a totally welded structure devoid of internal seals, ensuring robust compatibility with a wide range of fluids and gases. This version maintains the standard high-performance specifications of the series, including SIL2 functional safety approval according to IEC/EN 62061, making it an ideal choice for machinery manufacturers requiring precision measurement and functional reliability in atmospheres with flammable gases or dust.
Product Parameters
- Pressure Range: Available in measurement ranges from -1 to +1 bar up to 0 to 1000 bar.
- Output Signal: Standard amplified current output of 4-20 mA using a 2-wire system.
- Typical Accuracy: Measurement precision of ±0.15% Full Scale (FS) typical, with a maximum of ±0.2% FS.
- Supply Voltage: Operates on a standard power supply range of 10 to 30 Vdc.
- Temperature Class: Certified for T6, T5, & T4 temperature classification, supporting ambient and process temperatures up to +80°C.
- Protection Rating: Ingress protection levels ranging from IP65 to IP67 depending on the selected electrical connector.
- Functional Safety: Certified SIL CL 2 by TÜV Rheinland for use in high-demand mode safety applications.
- Housing Material: External casing and wetted parts constructed from AISI 304 and 17-4PH stainless steel.
- Response Time: Fast dynamic response of less than 1 millisecond for 10% to 90% FS changes.
Product Description
The KX series Non-Sparking variant provides a streamlined safety solution for Zone 2 hazardous areas, where explosive atmospheres are less likely to occur or exist only for short periods. Unlike intrinsically safe models that require external galvanic barriers, the Ex nA/ec protection mode focuses on the device’s ability to prevent sparks and excessive surface temperatures during normal operation. This design choice often simplifies electrical installation while maintaining high safety standards for chemical, pharmaceutical, and oil and gas facilities.
At the core of the transmitter is a sensing element deposited directly onto a stainless steel diaphragm using high-temperature screen printing. This thick film technology results in an extremely sturdy and reliable sensor capable of withstanding significant overpressure and burst pressures without degrading performance. The monolithic structure eliminates the need for internal O-rings or silicone oil filling, which prevents potential fluid contamination and mechanical failure due to seal degradation over time.
Functional safety is integrated into the series as a standard feature, rather than an optional add-on. The SIL2 certification ensures that the transmitter can be used as a primary sensing element in safety-related parts of a control system (SRP/CS), compliant with the European Machinery Directive. In the event of internal component failure, such as a broken bridge or supply issue, the transmitter enters a controlled alarm state by saturating the output signal below 3.6mA or above 24mA, allowing the controller to immediately identify a fault and trigger safety protocols.
The KX is also available as an intrinsically safe version.
Product Features
- ATEX Zone 2 certification for Non-Sparking (Ex nA) and Increased Safety (Ex ec) protection.
- SIL2 functional safety approval standard on all units for simplified system integration.
- Thick film on stainless steel sensing technology ensures high stability and long-term reliability.
- Totally welded metal structure with no internal seals or gaskets to leak or fail.
- Wide pressure measurement capability from vacuum levels up to 1000 bar gauge.
- Integrated pressure snubber option (0.5mm hole) to protect against cavitation and pressure peaks.
- Robust mechanical design with vibration resistance up to 20g and shock resistance to 100g.
- High-grade 17-4PH and AISI 304 stainless steel construction for excellent chemical compatibility.
Product Applications
- Zone 2 hazardous areas in oil and gas refineries and distribution centers.
- Chemical processing plants requiring robust measurement in flammable gas environments.
- Hydraulic and pneumatic systems in safety-critical industrial machinery.
- Power generation facilities utilizing gas-fired turbines or combustible fuels.
- Pharmaceutical manufacturing zones categorized for non-sparking electrical equipment.
- Large-scale compressors and pump stations prone to pressure peaks and vibration.
Product Specifying Guide
Determine the pressure range
Select the nominal pressure range required for your process. The series covers ranges from compound vacuum (-1 to +1 bar) up to extreme high pressures (1000 bar). Ensure that the expected operating pressure is within the compensated temperature range of -20 to +85°C for maximum accuracy.
Select the mechanical interface
Choose the pressure port thread that matches your existing manifold or pipework. Standard options include G 1/4 or G 1/2 gas male threads (DIN 3852-E) and 1/4” or 1/2” NPT male threads. For hydraulic applications with risk of cavitation, verify if the internal snubber option is necessary.
Choose electrical connection type
Match the electrical connector to your system’s cabling requirements. Options range from standard DIN 43650 Form A or Form C plugs to M12x1 circular connectors, multi-pole bayonets, or integral cables for permanent installations.
Verify certification requirements
Confirm that the ATEX Ex nA/ec certification for Zone 2 is appropriate for your installation site. If your application requires higher safety levels for Zone 0 or Zone 1, you may need to specify the intrinsically safe (Ex ia) variant instead.
Part Number Builder
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Installation & Operation Guide
Mechanical installation steps
Thread the sensor into the process port by hand to ensure no cross-threading occurs. Use a wrench on the hexagonal body (do not turn by the housing) and tighten to 30 Nm for standard ports. For DIN 3852-E connections, ensure the Viton sealing gasket is correctly seated.
Electrical wiring and loop setup
Wire the sensor in series with the 10-30 Vdc power supply and the receiving instrument. Always use shielded cables to prevent electromagnetic interference, grounding the shield only at the controller or safe-area side while leaving it floating at the sensor end.
Grounding the device
The transducer must be properly grounded to prevent electrical noise and ensure safety. This is normally achieved through the metal contact of the pressure port with the machine body or equipment it is installed on.
Troubleshooting the output
If the sensor provides an output below 3.6 mA, check for broken power supply cables, a disconnected sensor, or a failure in the bridge electronics. If the sensor outputs a saturated “HIGH” signal (above 24 mA), it may indicate a broken bridge or electronic overheating.
Periodic safety verification
To maintain the functional safety rating, conduct a sensor calibration test every four years. This involves applying known pressure points to the transducer and checking that the output signal accurately follows the transduction curve within the specified tolerance.
Product Help
Understanding Zone 2 protection
What is the advantage of using the Ex nA/ec version over an intrinsically safe model?
The Ex nA (Non-Sparking) and Ex ec (Increased Safety) protection modes are designed specifically for Zone 2 hazardous areas. The primary advantage is often a simplified installation process, as these devices generally do not require the use of external zener barriers or galvanic isolators required for intrinsically safe (Ex ia) circuits.
Managing pressure spikes
How does the sensor handle sudden pressure peaks in hydraulic circuits?
For applications with high-dynamic pressure pulsations, cavitation, or liquid hammer, the sensor can be supplied with an integrated pressure snubber. This snubber utilizes a 0.5mm diameter through-hole to dampen peaks and eliminate harmful phenomena that could otherwise damage the sensing diaphragm.
SIL2 reliability data
Can I use this transmitter in a high-demand safety loop?
Yes, the KX series is certified for “High Demand Mode” use by TÜV Rheinland in accordance with IEC/EN 62061. It has been tested to meet Safety Integrity Level 2 (SIL CL 2) requirements, making it suitable for use in safety-related programmable electronic control systems where pressure is the safety variable.
Maintenance of the pressure channel
What maintenance is required to keep the sensor working accurately in harsh environments?
Annual visual inspections should be conducted to check for any occlusion of the pressure channel. The inspection involves removing the probe from its process seat to ensure the channel is clear of any residue or material caps that could interfere with pressure transduction.
Ingress protection options
Which electrical connection offers the best environmental protection?
The environmental sealing depends on the connector chosen; for example, the M12x1 connector (Code Z) and the 7-pole M16 connector (Code P) provide an IP67 rating. The 6-pole bayonet (Code V) provides IP66, while the standard DIN connectors (Code E/M) are rated to IP65.
Related Documents
Specification data sheet
Request Product Price
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