Pressure Sensor - Industrial - Type KX | Gefran

Gefran KX Pressure Transmitter for ATEX Zones

The Gefran KX is a 4–20 mA, 2-wire pressure transmitter designed for hazardous areas with gas or dust atmospheres. The unit features a fully welded construction without internal elastomer seals, utilizing a thick film sensor on a stainless steel diaphragm. Wetted parts are compatible with 17-4PH and AISI 430F stainless steels.

Technical Data

• Measuring ranges: -1…+1 to 0…1000 bar
• Output: 4–20 mA, 2-wire
• Supply voltage: 10–30 Vdc
• Accuracy: ±0.15% FS typical / ±0.2% FS max
• Response time: < 1 ms
• Process temperature: -40…+125 °C
• Ambient temperature: -40…+105 °C (ATEX limits per T-class)
• Enclosure protection: IP65 to IP67
• Vibration: 20 g, 10–2000 Hz (IEC 60068-2-6)

ATEX / Ex Classification

KX series supports intrinsically safe applications with markings II 1G Ex ia IIC T6/T5/T4 Ga and II 1D Ex ia IIIC T200 90°C / 100°C / 110°C Da. Installation in hazardous areas requires connection to a certified [Ex ia] IIC galvanic isolation barrier (Uo ≤ 30 V, Io ≤ 100 mA, Po ≤ 0.75 W).

Process and Electrical Connections

Available process connections:

• G 1/4" male DIN 3852-E
• G 1/2" male DIN 3852-E
• 1/4”-18 NPT male
• 1/2”-14 NPT male

G 1/4 and G 1/2 connections use Viton sealing. Electrical interfaces: EN 175301-803 A/C, M12x1, 2-wire shielded cable, 7-pole screw, or 6-pole bayonet connector.

Pressure Spike Protection

For hydraulic blocks, pumps, or fast-closing valves where cavitation, water hammer, or pressure spikes may occur, the KX can be specified with an integrated 0.5 mm snubber to dampen transients before reaching the measuring diaphragm.

Standards and Certifications

KX is referenced under ATEX 2014/34/EU, PESO, SIL CL 2 (IEC/EN 62061), EMC 2014/30/EU, and RoHS 2011/65/EU. Calibration is traceable to international standards.

FAQ

When to select KX over KS or KM?
When pressure measurement is required in ATEX zones or an intrinsically safe 4–20 mA loop is needed.

Suitable media?
Liquids and gases compatible with 17-4PH and AISI 430F.

Maintenance checks?
Verify connection tightness, cable/connector condition, grounding, Ex barrier, loop load, and signal deviation.