AO3051 Isolated Smart Capacitive Transmitter

I. Overview

The AO3051 miniature membrane box capacitive transmitter is a compact transmitter produced by our company using advanced foreign technology and equipment. It employs imported key raw materials and components, boasts an advanced design principle, a full range of types and specifications, and is easy to install and use. This model combines the features of the widely used 3051 and EJA in the domestic market, offering unparalleled forward and backward compatibility. This ensures that you can avoid waste caused by outdated or premature products, thereby protecting your investment. To cater to the domestic automation level, this series includes two products: a standard analog output type and an intelligent type with HART fieldbus protocol.

Section II: Application Scope

The AO3051 transmitter is suitable for accurately measuring differential pressure from low to high, from low to high pressure, liquid level, vacuum degree, and specific gravity; with a throttling device, it can also measure flow rate.

III. Working Principle

Two pressures of the medium under test are introduced into the high and low pressure chambers, acting on the two isolation diaphragms of the δ element (i.e., the sensitive element). The transmission is achieved through the isolation diaphragms and the filled liquid within the δ element to the opposite sides of the pre-tensioned measuring diaphragm. Each measuring diaphragm, along with the electrodes on the two insulators, forms a capacitor. When there is no pressure introduced or the pressures on both sides are equal, the measuring diaphragm is in the middle position with equal capacitance in both capacitors. When the pressures on both sides are unequal, causing the measuring diaphragm to displace, the displacement is proportional to the pressure difference, resulting in unequal capacitance on both sides. The differential capacitance on this differential capacitor plate is detected, and then the electronic circuit converts and amplifies the differential capacitance into a 4-20 mA DC two-wire current signal. The working principle of the pressure transmitter and the pressure transmitter is the same as that of the differential pressure transmitter, the difference being that the pressure in the low-pressure chamber is atmospheric pressure or vacuum.

IV. Features

V. Technical Specifications

Regardless of the output, the range limits of positive and negative transfer shall not exceed the range limits.

Pressure Transmitter: 0-100 Base Range

Pressure transmitter: -100 to 100 Base Range

Temperature Range: Standard transmitter operating temperature -40℃ to +85℃; with现场指示表 on-site indicator -15℃ to +70℃

Storage Temperature: -40℃ to +100℃

Operating temperature for the filled silicone oil measuring element (medium temperature for LT type): -40℃ to +149℃

Remote transmitters filled with high-temperature silicone oil: -15℃ to +315℃; standard silicone oil: -40℃ to +149℃

Sensor volume change less than 0.16 cm³

Positive and Negative Transfer: Regardless of the output, the upper and lower limits of the range after positive and negative transfer must not exceed the range limits.

Pressure Transmitter: 0-100 Base Range

Differential Pressure Transmitter: -100 to 100 Base Range

Humidity Range: Relative humidity of 1~100%

Sensor volume change less than 0.16 cm³

Indicator Gauge (On-Site) - Pointer Type; Digital Display Type

Explosion-proof Type: Intrinsically Safe Type ia II CT6; Intrinsically Safe Type ia II CT6

Range and Zero Point: External Continuous Adjustment

Exceeding the pressure limit for applications below 6 MPa: 0 (pressure) to 14 MPa

Application Range: 0 (Pressure) to 32MPa; 20MPa Gauge Pressure

Application Range: 0 (Pressure) to 52MPa (42MPa Gauge)

Transmitter undamaged, flange capable of handling 60 MPa

The resistance can be continuously adjusted between 0 to 32 seconds.

Startup time: 2 seconds, no preheating required.

2. Performance Specifications

Integrated accuracy: ±0.1%, ±0.2% adjustment range

Standard accuracy is ±0.1%. If a different accuracy is required, please specify it during the order selection.

Stability: No more than transmitter accuracy within six months

Temperature Impact: At range (-10℃ - 60℃), every 30℃ variation: (Intelligent Model*) Range Code or Name, Accuracy Grade

0.1 Grade, 0.2 Grade

    2 / /

    3 / ≤±0.30%

    4、5、6、7、8 ≤±0.08% ≤±0.15%

Remote Control, Level

Static Pressure Influence Range Code or Name Accuracy Grade

0.1 Grade / 0.20 Grade

     2 / /

    3 / 0.5%

    4、5、6、7、8 0.10% 0.30%

4, 5, 6, 7 (High Pressure) / 2%

Vibration Impact: On any axis, at a frequency of 200Hz, the error is ±0.05%/g for a wide range (Scale Code 2, Differential Pressure) and ±0.25%/g.

Power Influence Less than 0.005%/V of the output range.

Load Impact: No impact when power is stable with no load.

The installation location can significantly affect the zero-point error, which may reach 0.24 KPa, but it is adjustable and does not impact the measurement range.

3. Performance Specifications

Structural Materials: 316 Stainless Steel, Hastelloy C, Inconel, Tantalum.

O-Ring (Medium Contact Area): Fluororubber

Flanges and Bolts: 316 Stainless Steel.

Filling Liquid: Silicone oil or inert oil.

Electrical Enclosure: Low copper aluminum alloy.

Bolt: Chrome-plated carbon steel

Pressure relief fittings - The connecting screw holes on the pressure vessel are 1/4 NPT, and the connecting screw holes on the pressure relief接头 are 1/2 NPT; the center distance can be seen in the dimensional drawings of various models.

Signal cable connection bolt hole is M20×1.5

Shell protection level IP65

Weight: 3.9 kg (excluding options, except with flanged transmitter)

-40°C to -10°C; temperature drift of 60°C to -85°C is 1.5 times the listed value.

Non-intelligent temperature drift is three times that of the intelligent type.

-40°C to -10°C; 60°C to -85°C temperature drift is 1.5 times the listed value.

The non-intelligent temperature drift is three times that of the intelligent type.

Section 6: Structural Dimensions

AO3051 Series Installation Diagram

AO3051 Series Dimensions Drawing