KELLER PD-39X Differential Pressure Transmitter

Core Performance & Industrial Application

The KELLER Series PD-39X is a differential pressure transmitter built on two absolute pressure sensors for indirect DP measurement.

It offers higher tolerance to one-sided unbalanced overloading than conventional diaphragm DP cells and keeps cost low for DP values above 5% of the standard range.

Microprocessor polynomial compensation eliminates sensor non-linearity and temperature drift, with 16-bit A/D conversion and 200 Hz true output rate.

It provides scalable analogue output (4-20mA 2-wire / 0-10V 3-wire) plus RS485 half-duplex Modbus RTU programming for zero/span scaling and flow square-root extraction.

It supports both positive and negative pressure ports with dual G1/4 connections per side for easy line mounting.

It is widely used as spare replacement in filter monitoring, pump DP, level and flow measurement systems.

Technical Specifications

▶ Product type: Differential pressure transmitter

▶ Brand: KELLER

▶ Model: Series PD-39X

▶ Standard pressure ranges: 3 / 10 / 35 bar; overpressure 10 / 30 / 100 bar

▶ Output: 4-20 mA 2-wire or 0-10 V 3-wire, freely scalable

▶ Communication: RS485 half-duplex, Modbus RTU

▶ Accuracy: ≤0.05% FS typ., ≤0.1% FS max.

▶ Resolution: 0.002% of standard range

▶ Supply voltage: 8 ~ 28 V DC

▶ Operating temperature: -40℃ ~ +100℃; compensated -10℃ ~ +80℃

▶ Wetted parts: 316L stainless steel (1.4435), Nitrile/Viton O-ring

▶ Process ports: G1/4 female, two per pressure side

▶ Protection rating: IP65

▶ Weight: Approx. 475 g

▶ Endurance: 10 million pressure cycles; 20 g vibration 20-5000 Hz

▶ Feature: Dual absolute sensors, polynomial temperature compensation, square-root flow output

▶ Country of origin: Switzerland

▶ Compliance: CE, EN 61000-6-1 to -4 EMC

Industry Applications

Applied in filter clogging monitoring, pump protection, tank level and DP flow measurement spare replacement in water, HVAC and process plants.

Note: Confirm standard pressure range, differential range, output type and electrical connection before ordering