Wholesale of PG20 series and PG3051 series static pressure liquid level transmitters and level gauges

1、 Principle of static pressure measurement
All types are based on the proportional relationship between hydrostatic pressure and liquid level height:P = ρ·g·H（PFor liquid static pressure,ρFor the density of the medium,gFor gravity acceleration,HFor liquid level height). The transmitter detects this pressure and converts it into a standard electrical signal (such as4–20mA）Output.

immersiveThe probe is directly immersed in the liquid, and the atmospheric pressure is compensated through a gas guiding cable to measure the static pressure of the liquid column.

side-mountedBy isolating the medium through flanges or capillaries, pressure is transmitted to the sensor to avoid contact with corrosive or viscous media.

two、Characteristics and Differences of Liquid Level Transmitters

1. Static pressure liquid level transmitter

Structure: Diffuse Silicon/Ceramic capacitive sensor, fully sealed stainless steel housing（IP68Protection).

Advantage:

High precision（0.1%~0.5%FS）Long term stability≤0.1%FS/Year.

Corrosion resistance（316LStainless steel diaphragm, high temperature resistance（-40~85℃）.

Applicable scenarios: Liquid level measurement of open or closed containers for clean water, sewage, oil, and mildly corrosive liquids, such as reservoirs and chemical storage tanks.

2. Input type liquid level transmitter

structureThe probe and transmitter are integrated or separated, directly inserted into the bottom of the liquid, and the air guide cable balances the atmospheric pressure.

advantage：

Easy installation (no flange connection required), strong vibration resistance, suitable for deep wells and underground water tanks.

Lightning protection design (some models come with a three-level lightning protection module).

limitationNot suitable for high viscosity or easily crystallizable media (which may clog the probe).

Typical ApplicationsHydrological monitoring, oil storage tanks, water supply systems.

3. Side mounted liquid level transmitter

Structure: Single/Double flange structure, pressure is transmitted through capillary filled with silicone oil, and the transmitter side is mounted on the container wall.

Classification:

Single flange: suitable for atmospheric or low-pressure containers, such as food and beverage cans.

Double flange: The high and low pressure flanges are respectively connected to the upper and lower parts of the container to measure the differential pressure liquid level, suitable for high pressure/High temperature media (such as reaction vessels).

Advantage:

Isolate sensors from media, resistant to strong corrosion and high viscosity (such as mud, acidic and alkaline liquids).

supportHARTProtocol remote calibration with low maintenance costs.

Typical applications: pharmaceutical reaction tanks, petrochemical pipelines, viscous media in the food industry.

3、 Comparison of key performance parameters

4、 Application Scenarios and Selection Guidelines

1. Scenario adaptation suggestions

static pressure type/immersiveClear water tank, sewage treatment plant (such as municipal water supply). Oil storage tanks (requiring explosion-proof certification).

Side mounted: Chemical reactor (strong acid, alkaline medium). Food and pharmaceuticals (require sanitary flanges, easy to clean). High viscosity media (such as pulp, crude oil).

2. Key factors for selection

Medium property: corrosive→Side mounted (Hastelloy alloy)/Tantalum film).

viscous/crystallization→Side mounted double flange (anti clogging).

Environmental requirements:

Explosion proof scenario→Intrinsic safety type（Exia）Or explosion-proof type（Exd）.

high temperature→Side mounted (silicone oil capillary resistant)300℃）.

Installation conditions:

narrow space→Input type (diameter can be as small asΦ22mm）.

Avoid medium contact→Side mounted (flange isolation).

5、 Key points for installation and maintenance

immersive：

The probe needs to sink to the bottom of the liquid and stay away from the inlet and outlet/Blender.

Regularly clean the membrane to prevent scaling (every6Monthly calibration).

side-mounted：

The flange installation should be parallel to the container wall, and the capillary tube should avoid bending.

High temperature environment requires the selection of high-temperature silicone oil filling fluid.

General maintenance：

Check the cable sealing (leakage prevention).

Intelligent transmitters can be used throughHARTRemote diagnosis of handheld devices.

summary

static pressure type/Input type: an economical solution suitable for measuring the liquid level of ordinary liquids, with easy installation but weak resistance to medium complexity.

Side mounted: a solution for high-risk working conditions (corrosion, high temperature, viscosity), with high maintenance costs but reliabilitygood.
Selection priority: Determine the medium first→Choose another type (side mounted)>input>Static pressure)→Finally match the range/Explosion proof rating. In practical applications, the proportion of side mounted double flange transmitters in the chemical industry exceeds60%Becoming a high demand scenariochoice.