SMT3151LT Pressure Level Transmitter

Pressure level transmitter is good for level measurement. Most of the time, we use submersible hydrostatic level sensor for the level measurement. When you can not use the probe of hydrostatic level sensor, you can try with this pressure level transmitter. Pressure level transmitter, is one type of DP level measure instrument, with the diaphragm.

The liquid level (pressure/differential pressure) transmitter,

is a pressure signal, measured at the reference side of atmospheric pressure (a low-pressure side),

with one or two ports for flange (or other connection) and process pipe connection.

So, we can say that the SMT3151LT pressure level transmitter,

also is one kind of diaphragm type level transmitter.

A pressure level transmitter is an on-site transmitter, that is mounted directly on a pipe or vessel.

Since the isolating diaphragm is directly in contact with the liquid medium,

it is not necessary to take out the pressure guiding tube on the positive pressure side,

so that the liquid level (Magnetostrictive level gauge), pressure, and density of the medium,

such as high temperature, high viscosity, easy crystallization,

easy precipitation and strong corrosion can be measured,

and then It is converted to 4~20mA.DC signal output

Features of SMT3151LT Pressure level transmitter

pressure level transmitter
  • 0-2.1Mpa
  • -40~204℃
  • Flange-mounted
  • 4-20mA, HART
  • 316 stainless steel
  • Explosion-proof

Working Principle of pressure level transmitters:

DP Level Technology

On the basis of common pressure/differential pressure transmitter,

one or two isolation membrane boxes are added to measure the liquid receiving part.

Mainly used for measuring high temperature,

easy to solidify or crystallize,

containing solid suspended matter, too viscous,

corrosive or other needs to maintain sanitary conditions, non-polluting media.

The basic measurement element,

is the same as the technical performance,

and technical index of the 3151 pressure/differential pressure transmitter.

After adding the remote transmission device,

there will be a small decrease in measurement accuracy,

slow reaction speed,

and the installation position should be attended to,

when the pressure is relatively small,

so as to ensure that the measured pressure is within the measurement range,

of the basic measurement element.

In other words, a column of water of a specific height,

will always exert the same amount of pressure on a transducer.

And because weight is a force, and pressure is force applied over an area,

in this case, the area of the transducer,

we can take the pressure reading from the transducer and translate it into a level.

Extended reading: Flat Pressure Sensor for High Viscosity Fluids

What is the working principle of level transmitter?

There are many different kinds of level measurement transmitters, including:

  • Capacitance
  • Hydrostatic
  • Magnetic
  • Radar
  • Ultrasonic
  • Guided Microwave

Each of these transmitters works in different ways, making them useful for different types of processes.

These transmitters use liquid stored in a tank or container,as a dielectric medium between two or more electrodes.The energy capacity of the capacitor circuit increases,when there is more liquid and decreases if there is less liquid. By measuring the variations in the capacitance value,capacitance level transmitters can calculate the current fill level of the tank or container.

Capacitance Level Transmitters:

  • Hydrostatic Level Transmitters::

Also known as pressure level transmitters,these transmitters help in determining fluid contents of a container,by measuring the pressure of the resting body of the fluid within it. The greater the force of liquid, the greater the volume of fluid.

Read more about: Hydrostatic level measurement: Measuring Principle

  • Magnetic Level Transmitters:

These transmitters use a magnetic object,which is suspended in a buoyant float.This is usually in a narrow auxiliary column,to restrict lateral movements of the float.While the float is on top of the liquid,the movement of the float is measured by a different magnetic device.This allows a precise and stable fill level to be transmitted.This method is suitable for continuous measurement,owing to the tendency of the float to rise or sink based on the liquid level.

New: SI-LT Magnetostrictive level transmitter with Local Digital Display

These transmitters work on the principle of radar by using radio wave emissions.These transmitters are normally mounted at the top of a tank filled with a liquid.The transmitter sends a radar signal into the liquid and receives a reflection of the signal.The transmitters then analyze the current fill level of the tank based on the time taken by the transmitted signal to return.

In this type of transmitter, an ultrasonic transducer is mounted at,or near the top of a container containing liquid.The transducer sends out an ultrasonic pulse.The pulse hits the surface of the liquid and gets reflected.The sensor then calculates the fill level based on the time between the transmitted and received signal.

  • Guided Microwave Level Transmitters:

These transmitters work by sending a microwave pulse,through a sensor cable or rod.The signal hits the surface of the liquid,and travels back to the sensor,and then to the transmitter housing.The electronics integrated into the transmitter housingdetermine the filling level based on the time,taken by the signal to travel down the sensor and back up again.These types of level transmitters are used in industrial applications,in all areas of process technology.

How do you use a DP transmitter for level measurement?

How does a hydrostatic level transmitter work?

Hydrostatic pressure for level measurement:

SI-151 Hydrostatic Level Sensor
SMT3151TR Hydrostatic level transmitter-Rod Type
SI-PCM260 Deep Well Water Level Sensor

Featured Continuous level sensors

SI-U01 Float Level Sensor
SI-U02 Multi-Point Liquid Level Float Switch
SI-U03 Float Switch Water Level Controller
SI-U04 Magnetic Float Level Sensor-Reed Switch

Pressure level transmitter manufacturer

Sino-Instrument, we are the pressure level transmitter manufacturer in China.

We supply SMT3151LT pressure level transmitters.

We offer flamges:

  • DN50 (2″)
  • DN80 (3″)
  • DN100 (4″)
  • DN40
  • Flush flange
  • Insert barrel flange

And for the material of diaphragm, we offer :

316 Stainless steel
Hastelloy C
Special requirements

If you need to know more about the SMT3151LT pressure level transmitters,

you can refer to the :

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About KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects. Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.