Figure 1: APT 3100 smart pressure transmitter.
With the rapid rise of fieldbus technology, the industrial process control system is gradually developing towards fieldbus control system (FCS) with two-way communication and smart instrument control, bring about the smart pressure transmitter.
The main features of the smart pressure transmitter are: reverse polarity and current limiting protection, laser resistance adjustment temperature compensation, wide range, anti-corrosion, suitable for a variety of media, strong overload and anti-interference ability, stable performance, unique display table design, optional analog and digital display heads; it can be adjusted by the hand-held communicator at the zero point and full scale, and the range shift range is wide.
The general characteristics, the characteristics in terms of the analog type and the smart type are introduced in detail.
The General Characteristics
The smart pressure transmitter generally has:
1) Automatic compensation capability. It can automatically compensate the nonlinearity, temperature drift, time drift, etc. of the sensor through software.
2) Self-diagnosis. After power-on, the transmitter can be self-tested to check whether each part of the transmitter is normal and make a judgment.
3) Convenient and accurate data processing. The data can be automatically processed according to internal procedures, such as statistical processing, removal of abnormal values, etc.
4) Two-way communication function. The microprocessor can not only receive and process transmitter data, but also feed back information to the transmitter to regulate and control the measurement process. It can carry out information storage and memory, and can store the characteristic data, configuration information and compensation characteristics of the transmitter.
5) Digital interface output function. It can easily connect the output digital signal with computer or field bus.
Figure 2: A Modbus micro smart pressure transmitter.
Characteristics of the Analog Type
1) High precision;
2) Span and zero point are continuously adjustable externally;
3) Good stability;
4) Positive migration up to 500%, negative migration up to 600%;
5) Two-wire;
6) Adjustable damping, overvoltage resistance;
7) Solid state transmitter design;
8) No mechanical moving parts, less maintenance;
9) Light weight (2.5kg);
10) The whole series has a unified structure and strong interchangeability;
11) Miniaturization (166mm total height);
12) Optional diaphragm material in contact with the medium;
13) Unilateral overpressure resistance;
14) Low pressure cast aluminum alloy housing.
Characteristics of the Smart Type
The smart pressure transmitter has superior measurement performance for pressure, differential pressure, level, flow rate measurement. Besides, it also has these characteristics:
| Specifications | |
| Accuracy | +(-)0.05% |
| Accuracy of analog | +(-)0.75%+(-)0.1% F.S |
| Stability | 0.25% 60 months |
| Turndown ratio | 100:1 |
| Measurement rate | 0.2 S |
1) Miniaturized (2.4kg), all stainless steel flange, easy to install;
2) Compatible with other products in process connection for optimum measurement;
3) Using 16-bit computer;
4) Standard 4-20mA, with digital signal based on HART protocol, remote control;
5) Support for upgrades to fieldbus and field control based technologies.
Related Info
How to Maintain a Pressure Transmitter?What is a Smart Pressure Transmitter?
How to Deal with Spindle Amplifier Alarm Codes?
What is a Pressure Transmitter?
10 Things to Consider when Choosing a Pressure Transmitter
