Pressure type liquid level transmitterWorking principle
Principle of static pressure measurement:
When the liquid level transmitter is inserted into a certain depth of the measured liquid, the pressure formula on the sensor facing the liquid level is: Ρ = ρ .g.H + Po
In the formula:
P ： Pressure exerted on the liquid level of the transmitter
ρ： Density of the tested liquid
g ： local gravitational acceleration
Po ： Atmospheric pressure on the liquid surface
H ： Depth of liquid input into the transmitter
At the same time, the pressure of the liquid is introduced into the positive pressure chamber of the sensor through gas guiding stainless steel, and the atmospheric pressure Po on the liquid surface is connected to the negative pressure chamber of the sensor to offset the Po on the back of the sensor, so that the pressure measured by the sensor is: ρ .g.H ， Obviously, by measuring the pressure P, the depth of the liquid level can be obtained.
Functional Features
Good stability, with long-term stability of up to 0.1% FS/year at full and zero positions. Within the compensation temperature range of 0-70 ℃, the temperature drift is less than 0.1% FS, and within the entire allowable operating temperature range, it is less than 0.3% FS.
◆ Equipped with reverse protection and current limiting protection circuits, the transmitter will not be damaged if the positive and negative poles are reversed during installation. In case of abnormalities, the transmitter will automatically limit the current to within 35MA.
Solid state structure, no movable parts, high reliability, long service life.
Easy installation, simple structure, economical and durable.
Main technical parameters:
Measurement range:
Process: Diffusion silicon ceramic capacitor, sapphire capacitor, optional
Split type integrated optional
Range: 0-0.5-200 meters
Output: 4-20mA (2-wire system)
Power supply: 7.5-36VDC recommended 24VDC
Performance and advantages
Its mechanical structure has high resistance to overload and corrosive media
High precision, long-term stable ceramic capacitors and imported diffused silicon measurement units
Sealed electronic module and dual filtering pressure compensation system can resist the impact of climate field changes
An electronic module that can output 4... 20mA signals and is equipped with overvoltage protection
Choosing the integrated temperature sensor Pt100 can simultaneously measure the level and temperature of the material
The corresponding attachments can provide a complete measurement plan
Simulation Characteristics
● High precision
● Range and zero point can be continuously adjusted externally
● Good stability performance
Positive migration can reach 500%, negative migration can reach 600%
● Two line system
Adjustable damping and overvoltage resistance
Solid state sensor design
No mechanical movable parts, low maintenance volume
● Lightweight (2.4kg)
● Unified structure and strong interchangeability across the entire series
● Miniaturization (166mm total height)
The membrane material that comes into contact with the medium is optional
● Unilateral overpressure resistance
Low pressure cast aluminum alloy shell
Intelligent features:
Super measurement performance, used for pressure, differential pressure, liquid level, and flow measurement
● Digital accuracy:+ （-）0.05%
Simulation accuracy:+ （-）0.75%+（-）0.1%F.S
● Full performance:+ （-）0.25F.S
Stability: 0.25% for 60 months
Range ratio: 100:1
Measurement rate: 0.2S
● Miniature (2.4kg) all stainless steel flange, easy to install
● Process connection is compatible with other products to achieve optimal measurement
The world's * sensor (technology) using H-alloy sheath has achieved excellent cold and hot stability
Intelligent transmitter using 16 bit computer
Standard 4-20mA, with digital signal based on HART protocol, remote control
● Support upgrades to fieldbus and field control based technologies.