Pressure Transmitter Meter Capaitance Sensor Differential Pressure Absolute Pressure

General Introduction

NCS-PT105Ⅱ series Smart Pressure Transmitter with advanced, mature, reliable 3151 capacitance sensors has been designed meticulously by combining advanced microprocessor technology and digital capacitance measurement technology. The powerful functions and high-speed computing capability of the microprocessor make it have excellent qualifications such as smart, high precision, high reliability, stable zero and so on. Its LCD can display many physical parameters (e.g. pressure, temperature, current and so on). It can realize the functions such as zero adjustment, range settings by key-press operation, and it is easy for field testing.

NCS-PT105Ⅱ series Smart Pressure Transmitter supports HART, FF, and PA protocol and can measure pressure, differential pressure, liquid level, flow, and other industrial parameters. It can be widely used in the petroleum, chemicals, electricity, and metallurgical industries, etc..

Feature

Excellent Performance

-- High precision: ±0.075% full range (20℃, within the range of 10:1)

-- Long-term stability: ±0.1% of the maximum range within 12 months

Flexibility

-- Pressure type selection (micro differential pressure, surface pressure, absolute pressure, differential pressure, high static differential pressure)

-- Parameters can be set by magnetic bar, hand operator and upper computer software

-- High range ratio (100:1)

Reliability

-- Self-detection function (sensor, memory, communication)

-- Automatic compensation function (ambient temperature compensation, sensor input linearization)

-- Software and hardware fault alarm function

-- Configuration protection: EEPROM write protection function

GSD and DT

SIze of 4-20ma Output Signal Multi Protocol 3051 Differential Pressure Transmitter (Capacitance Sensor)

Introduction for Working Principle

The widely used 3151 capacitive pressure sensors, which were developed by Rosemount initially in USA, have been produced on a large scale in China. The core of its sensor is differential capacitive membrane, as Figure 3-2 shows. There are two measurement capacitances CH and CL distributed in differential capacitive membrane. The two measurement capacitances are almost equal to two plate capacitances because of their mechanical structure. The two measurement capacitances share one polar plate, which is a measure membrane in the center. And the other polar plate is fixed on the two sides. When the pressures of two sides are equal, the measure membrane is in the center, the capacitances of two sides are equal too. But when the pressure of high pressure side is higher than that of low pressure side, the guide pressure liquid filled in the membrane guides the differential pressure, so that the measure membrane moves to low pressure side. As a result, the capacitance of high pressure side is lower than that of the low pressure side.

Wiring

The power and signal of Smart Transmitter are sharing one pair of cables (Bus Cable). The ordinary cables can be selected by HART smart transmitter, but FF, PA Smart Transmitter is suggested to use specific Fieldbus cable the IEC61158-2 recommended. The terminal is at the rear cover, the terminal wiring board could be seen after screwing the rear cover (indicated “FIELD TERMINAL”).

                               FF,PA Smart Transmitter Wiring                                                  HART Smart Transmitter Wiring

Basic Parameters

Performance Index

How To Choose NCS-PT105II Pressure Transmitter (Capacitance Sensor)?