Products
Introduction:
The general sense of the pressure transmitter is mainly by the pressure element sensor (also known as pressure sensor), measurement circuit and process connectors are composed of three parts. It can be sensed by the pressure element sensor gas, liquid and other physical pressure parameters into standard electrical signals (such as 4 ~ 20mADC, etc.), in order to supply the indication of alarms, recorders, regulators and other secondary instruments for measurement, indication and process regulation.
Principle of operation.
The two pressures of the measured medium are passed into the high and low pressure chambers, which act on the isolation diaphragms on both sides of the δ-element (i.e., the sensitive element), and are transmitted to both sides of the measurement diaphragm through the isolation piece and the filling liquid inside the element. Capacitive pressure transmitter is composed of a capacitor on each side of the measuring diaphragm and the electrodes on both sides of the insulating sheet. When the two sides of the pressure is not consistent, resulting in the measurement of diaphragm displacement, its displacement and pressure difference is proportional to the two sides of the capacitance is not equal, through the oscillation and demodulation link, converted into a signal proportional to the pressure. Capacitive pressure transmitter and capacitive *** pressure transmitter working principle and differential pressure transmitter is the same, the difference is that the low pressure chamber pressure is atmospheric pressure or vacuum. The A/D converter of the capacitive pressure transmitter converts the demodulator current into a digital signal, the value of which is used by the microprocessor to determine the input pressure value. The microprocessor controls the operation of the transmitter. In addition, it performs sensor linearization. Resets the measuring range. Engineering unit conversions, damping, open-square,, sensor trimming and other operations, as well as diagnostics and digital communications.
Structural Analysis:
The pressure transmitter microprocessor has 16 bytes of program RAM and has three 16-bit counters, one of which performs the A / D conversion.
D / A converter to the microprocessor and corrected by the digital signal fine-tuning data, these data can be modified by the transmitter software. The data is stored in EEPROM and remains intact even in the event of a power failure.
A digital communication line provides the transmitter with an interface to external devices such as the Model 205 Intelligent Communicator or control systems utilizing the HART protocol. This line detects the digital signal superimposed on the 4-20 mA signal and transmits the required information through the loop. The type of communication is frequency-shifted keyed FSK technology and is based on the BeII202 standard.
Features:
l Digital accuracy: + (-) 0.075%.
l Stability: 0.075% for 60 months.
l Measurement range ratio: 100:1
l Measurement rate: 0.2S
l Compact (2.4kg) all stainless steel flange, easy to install
l process connection compatible with other products, to realize *** measurement
l The world *** using H alloy sheath sensor (patented technology), to achieve excellent cold and thermal stability
l Intelligent transmitter with 16-bit computer
l Standard 4~20m.
l Supports upgrading to fieldbus and field control-based technology.
Advantageous analysis:
Analog type features
High accuracy
Continuously adjustable external range and zero point.
Good stability
● Positive migration of up to 500%, negative migration of up to 600%.
● Two-wire system
● Adjustable damping, overvoltage resistance
Solid-state sensor design
No mechanical moving parts, low maintenance ● Light weight (2.4kg)
● Light weight (2.4kg)
Light weight (2.4kg) ● Unified structure for the entire series, high interchangeability
Compact size (166mm total height)
● Optional diaphragm material for contact with media
● Strong resistance to overpressure on one side
Low-pressure cast aluminum alloy housing
Intelligent features:
● Superb measurement performance for pressure, differential pressure, liquid level, and flow measurement
●Digital accuracy: +(-)0.05%
●Analog accuracy: +(-)0.75%+(-)0.1%F.S
●Full performance: + (-) 0.25F.S
●Stability: 0.25% 60 months
●Range ratio: 100:1
●Measurement rate: 0.2S
●Miniaturized (2.4kg) all stainless steel flange for easy installation
●Process connection compatible with other products to realize *** measurement
***The world*** adopts the H alloy sheath sensor (patented technology), realizing excellent cold and heat stability.
●Intelligent transmitter with a 16-bit computer
●Standard 4-20mA with digital signal based on HART protocol, remote control
●Supports upgrading to fieldbus and field control based technology.
Technical Parameters:
Analog: 2-wire 4～20mADC
Digital: 2-wire 4～20mADC with digital signals of process variables in accordance with HART protocol.
Power supply: supply voltage 12.5 ~ 45VDC
Load Limit: Loop *** load resistance Rmax depends on the supply voltage, HART communication requires load resistance of not less than 250Ω, not more than 600Ω.
Communication distance: *** communication distance is 1.5Km, multi-station communication can be connected to a maximum of 15 smart transmitters.
Output display: four-digit digital display, five LCD liquid crystal display, pointer type.
Explosion-proof type: Intrinsically safe: ExiaII CT5; explosion-proof type.
Zero migration range: The zero point can be migrated positively or negatively at will, but the upper and lower limits of the set measurement range and the range shall not exceed the limit value.
Temperature range: Ambient temperature: -40～85℃ (-20～70℃ when LCD indicator is selected)
Measuring medium temperature: -40～104°C
Static pressure and one-way overpressure range: 3.45Kpa (absolute pressure) ~ 31.2MPa (gauge pressure)
Relative humidity: 5～98%RH
Start-up time: within 5 seconds
Volume change: less than 0.16cm3
Adjustment of damping: 0.20～25 seconds of normal time
Failure alarm: If the sensor or circuit failure, the automatic diagnostic function will automatically output 3.9 or 21.0mA.
Configuration protection: In order to avoid arbitrary changes in the configuration data of the transmitter, you can lock the stored data through the software or protection switch.
