In the process of industrial process control and technical measurement, mechanical pressure gauges have become more and more widely used due to their high mechanical strength and ease of production.
的弹性敏感元件随着压力的变化而产生弹性变形。 The elastic sensitive element of the mechanical pressure gauge is elastically deformed as the pressure changes. The mechanical pressure gauge adopts spring tube (Bourdon tube), diaphragm, diaphragm box and bellows and other sensitive components and is classified according to this. The measured pressure is generally regarded as relative pressure.
Generally, the relative point is selected as atmospheric pressure. The elastic deformation of the elastic element under the action of the medium pressure is enlarged by the gear transmission mechanism of the pressure gauge, and the pressure gauge will show the relative value (high or low) relative to the atmospheric pressure.
The pressure value in the measurement range is displayed by the pointer, and the indication range of the scale is generally made 270 degrees.
Classification of pressure gauges:
Pressure gauges can be divided into precision pressure gauges and general pressure gauges according to their measurement accuracy. The accuracy levels of precision pressure gauges are 0.1, 0.16, 0.25, and 0.4; the accuracy levels of general pressure gauges are 1.0, 1.6, 2.5, and 4.0.
Pressure gauges are divided into general pressure gauges, absolute pressure gauges, and differential pressure gauges according to the basis of their indicated pressure. General pressure gauges are based on atmospheric pressure; absolute pressure gauges are based on absolute zero pressure; differential pressure gauges measure the difference between two measured pressures.
Pressure gauges are divided into vacuum gauges, pressure vacuum gauges, micro pressure gauges, low pressure gauges, medium pressure gauges, and high pressure gauges according to their measurement ranges. Vacuum gauges are used to measure pressure values below atmospheric pressure; pressure vacuum gauges are used to measure pressure values below and above atmospheric pressure;
Micro pressure gauges are used to measure pressure values less than 60000 Pa; low pressure gauges are used to measure pressure values from 0 to 6 MPa; medium pressure gauges are used to measure pressure values from 10 to 60 MPa; high pressure gauges are used to measure pressure values above 100 MPa.
的壳体制成全密封结构，且在壳体内填充阻尼油，由于其阻尼作用可以使用在工作环境振动或介质压力（载荷）脉动的测量场所。 The housing of the shock-resistant pressure gauge is made of a fully sealed structure, and the housing is filled with damping oil. Due to its damping effect, it can be used in measuring places where the working environment is vibrating or the medium pressure (load) is pulsating.
The pressure gauge with electric contact control switch can realize alarm or control function.
The pressure gauge with remote transmission mechanism can provide electrical signals (such as resistance signals or standard DC current signals) required in industrial engineering.
The isolator (chemical seal) used in the diaphragm meter can isolate the measured medium from the instrument through the isolation diaphragm in order to measure the pressure of strong corrosion, high temperature, and easily crystallized media.
Elastic element of pressure gauge The elastic sensitive element in the mechanical pressure gauge is elastically deformed as the pressure changes. Mechanical pressure gauges use sensitive components such as spring tubes (bourdon tubes), diaphragms, capsules and bellows and are classified according to this. Sensitive components are generally made of copper alloy,
Stainless steel or made of special materials.
Spring tube (Bourdon tube) is divided into C-type tube, coil spring tube, spiral tube and other types. Generally, cold-work hardened material blank tubes are used, which have a high degree of plasticity in the annealed state, and obtains high elasticity and strength after cold working hardening and qualitative treatment. Spring tube pressure
Under the action, using its elastic characteristics, the pressure can be easily converted into the elastic displacement of the free end of the spring tube. The measuring range of spring tube is generally 0.1MPa ~ 250MPa.
The diaphragm sensitive element is a circular diaphragm with a wave. The diaphragm itself is located between the two flanges or welded on the flange or the edge is sandwiched between the two flanges. The diaphragm is under pressure from the measuring medium. In this way, the small bending deformation caused by the diaphragm can be used
To indirectly measure the pressure of the medium. The amount of pressure is indicated by the pointer. Compared with Bourdon tube, the diaphragm has larger transmission force. Because the diaphragm itself is fixed around the edges, its vibration resistance is good. The diaphragm pressure gauge can achieve high over-pressure protection (for example, the diaphragm is attached to the upper flange).
The diaphragm can also be added with a protective coating to improve corrosion resistance. Using open flanges, flushing, openings and other measures, diaphragm pressure gauges can be used to measure very viscous, unclean and crystalline media. The pressure measurement range of the diaphragm pressure gauge is 1600Pa ~ 2.5 MPa. Capsule sensor
It consists of two pairs of diaphragms with a circular wavy cross-section. The pressure of the measuring medium acts on the inside of the capsule cavity, and the resulting deformation can be used to indirectly measure the pressure of the medium. The magnitude of the pressure value is displayed by the pointer. The capsule pressure gauge is generally used to measure the micro pressure of gas.
And has a certain degree of over-voltage protection. The stacking of several capsule sensitive elements will produce a large transmission force to measure extremely small pressures. 的压力测量范围在250Pa ~ 60000Pa。 The pressure range of the capsule pressure gauge is from 250Pa to 60000Pa.