General Overview
The PD61 transmitter is designed for differential pressure and flow measurements in gases, vapours, and liquids. It supports nominal pressures of PN160 and PN420 and outputs a standard 4-20 mA signal proportional to the measured differential pressure, flow, or level. The device operates on a two-wire principle and is powered by DC voltage.

Description
The PD61 consists of a measuring cell, process flanges with seals, and an electronic housing. It offers seven measuring cell versions with spans ranging from 1 to 40,000 mbar. The process flanges, which are in contact with the media, are available in various materials, and the seals can be made from FKM, PTFE, NBR, or Copper. The housing can be rotated 360° to accommodate different pressure line arrangements.

Operating Principle
The measuring cell uses a piezoresistive silicone element and metallic sealing diaphragms filled with silicone or inert oil. Changes in differential pressure displace the diaphragms, altering the sensor's bridge balance, which corresponds to the applied pressure. The microprocessor monitors these values and provides an alarm signal if discrepancies occur.

Technical Data
Input: Supports measuring cells PN160 and PN420 with a static pressure effect and overload limit.
Output Signal: Standard 4-20 mA signal with HART communication protocol. Failure signals are adjustable, and the device supports a ripple of ±0.25% fsd.
Dynamic Response: Warm-up delay is less than 10 seconds, with adjustable damping.
Power Supply: Requires a supply voltage of 10.5-45 VDC, with specific requirements for explosion-proof models.

Environmental Conditions
The transmitter operates in temperatures ranging from -40 to +85°C and can handle 100% relative humidity. It complies with various standards for electromagnetic compatibility and pressure equipment directives.

Mounting and Accessories
The PD61 can be mounted on pipes or walls using a bracket or valve manifold. It includes accessories like venting valves and a quick start manual.

Explosion Protection
The device is certified for ATEX II G1/2 explosion protection and includes a certificate of conformity.

Materials and Construction
The electronic housing is made from die-cast aluminium with a chromated surface and epoxy polyester coating. The process coupling uses a ¼-18NPT-f thread, with other options available.

Additional Documentation
Includes an instruction manual, ATEX safety instructions, and a SIL certificate.