First, pirani vacuum gauge.
1. pirani vacuum gauge principle heats the resistance wire to the required working temperature. Because gas particles collide with the resistance wire and take away energy, the temperature of the resistance wire will change. The energy loss of the hot wire is directly proportional to the gas concentration and gas composition around the hot wire.
2. Two types of pirani rules are derived.
1) and measure the change of applied voltage to measure the vacuum equivalent.
2) Stabilize voltage and measure temperature change to measure vacuum equivalent (thermocouple gauge).
3. The heat conduction of gas is related to the following conditions:
1) gas type 2) pressure.
4. pirani vacuum gauge measuring range and precision measuring range (air, oxygen, carbon monoxide, nitrogen): 5 x 10-4 to 1000 millibar precision (nitrogen):1x/kloc-0-3 ...1.
5. The excellent characteristics of pirani vacuum gauge protect the filament to the maximum extent without affecting the accuracy and speed, and greatly prolong the service life of the filament.
6. The specific model of pirani vacuum gauge.
Pirani capacitance diaphragm composite vacuum gauge
1) pirani gauge and special ceramic membrane gauge are combined together.
2) The whole adjustment process in which the two principles work.
3) 100 millibar-1000 millibar uses the signal of the membrane manometer.
4) Simultaneously use 1 millibar–100 millibar signal.
5) 5x10-4mbar–1mbar adopts pirani signal.
6) The output vacuum signal (voltage) is continuous without jumping.
7) Pre-stage pressure measurement of various high vacuum pumps in pirani vacuum gauge application industries, such as photovoltaic, coating and plasma industries, such as lighting, metallurgical L vacuum interlocking control and high vacuum gauge ignition switch control.
Second, the capacitance film gauge
1. working principle of capacitive thin film strain gauge l pressure deforms the diaphragm, and the deformation is proportional to the pressure. L Measure the vacuum degree by measuring the deformation of ceramic diaphragm under different pressures.
2. Capacitive thin film manometer has the following characteristics: l Based on reliable ultrapure ceramic sensor room; L Stable and reliable high-precision pressure measurement in harsh and corrosive environment; L fast preheating and recovery time to improve productivity; L Excellent long-term stability, reproducibility and repeatability; L Because the electronic components are directly installed on the sensor, the temperature compensation and EMC compatibility are improved, and the sensitivity to the change of environmental conditions is reduced, so that the measurement is more stable, quickly preheated, quickly stabilized and enters the standby state within one minute after starting; And one button: zero function and set point adjustment. Corrosion-resistant ultra-pure ceramic sensor can withstand millions of pressure cycles including atmospheric pressure impact, without any signs of degradation, and quickly recover after exposure to atmospheric pressure. Without isolation valve, L is insensitive to steam medium, and L's advanced sensor shielding (patent) prolongs the service life of vacuum gauge in the process of pollution.
3. Advantages of ceramic technology
1) has no memory effect.
2) Ceramics have no fatigue problems.
3) Optimal temperature compensation
4) Good zero stability and low use cost.
5) Extraordinary service life
6) No isolation valve is needed.
4. Measuring range
5. Hot film pressure gauge
6. Advantages of heating type L Zero drift is extremely small 0. 1%FS/ year (clean vacuum environment) L Accuracy is higher L Ambient temperature change/ambient pressure change/ambient air flow change has no effect on accuracy L Preheating start time is faster than the process L Fast recovery time atmospheric pressure.
7. The application of capacitive thin film strain gauge requires high application conditions. Accurate and rapid pressure measurement L is used for manufacturing semiconductor devices such as etching, CVD, PVD and ALD, such as PECVD in solar photovoltaic industry, and ceramic type is generally used for etching, with good anti-pollution performance.
Third, thermoelectric deviation.
1. Thermoelectricity deviates from Richardson effect principle: high-temperature filament emits electrons, high-energy electrons collide with gas molecules, and one or more electrons of gas molecules are knocked out to form positively charged ions.
1) charged ions are captured by an ion collector, collected and amplified, and then output.
2) The ion flow rate is proportional to the gas pressure.
2. Two types of thermoelectric deviation gauges
3. Thermoelectric release composite pressure gauge L HP G400L BPG400/-SP/-SD/SR L BPG402L BCG 450b-A pressure gauge, pirani pressure gauge and membrane pressure gauge are combined together.
4. Advantages and applications: l BPG n has a wide measuring range, and a pressure gauge covers the measuring range of 13 5x10-10–1000 mbar n, which has high accuracy and excellent repeatability. The 5% nYttrium iridium-plated filament has excellent oxidation resistance, and the pirani self-locking protection prevents the filament from burning due to sudden exposure to the atmosphere. N is convenient for calibration and adjustment. N Note: U is selective for gas, and U is weak in anti-pollution. N is widely used for measuring from low to ultra-high vacuum, and N is widely used in industry, semiconductor and scientific research industries. l BPG402 n double filament greatly prolongs the service life, and the work of N ionization gauge can customize the calibration parameters of N probe spare parts. Ensure accuracy and repeatability l HPG400 n ionization gauge and Pirani's compound N Pirani self-locking protection ionization gauge N The working starting point of ionization gauge can be customized within a certain range N Simple calibration function N Relatively cheap price l BCG450 n Adjustable ionization gauge working starting point N Excellent repeatability N Accurate atmospheric endpoint measurement.
Fourthly, the cold ionization gauge (Pan Ning gauge).
1. The principle of cold ionization gauge is to generate electrons through gas discharge, and the electrons gain energy through magnetic field to ionize gas molecules. 2. Characteristics and application of Pan Ning gauge L Measurement range: 5x 10-9 to 0x 1x 10-2 mbar L All-metal seal L Filament-free L Easy cleaning L Suitable for ordinary high vacuum measurement.
3. The characteristics and application of 3.MPG400 cold heading machine. The composite measuring range of cold gauge and pirani gauge is very wide: 5x 10-9- 1000 mbar. Easy to maintain and clean. L no high vacuum filament, l for ordinary high vacuum measurement.