U-type pressure vacuum gauge

1、 Overview:

1. The U-type pressure vacuum gauge (hereinafter referred to as vacuum gauge) is an ideal instrument for measuring the crude vacuum pressure. It is small and beautiful in structure, light in weight and convenient in installation and operation. It is characterized by high precision, fast response, wide measuring range, stable and reliable, stainless steel parts and components, and high corrosion resistance, which are incomparable to other pressure vacuum meters. It can be used in metallurgy, chemical industry, petroleum, light industry, medicine, scientific experiment and lithium bromide refrigeration unit of central air conditioner. So it is an ideal instrument welcomed by users.

2、 Main technical indicators:

The measuring range is 0-15kpa 0-30kpa

Accuracy class 1.0

3、 Working environment conditions:

Ambient temperature: - 5 -- 35 ℃

Relative humidity: ≤ 85%

4、 Working principle:

The vacuum gauge is a kind of liquid pressure gauge. Its basic principle is to use the principle of hydrostatic balance, the use of liquid height and direct pressure measurement instrument. The two ends of the glass tube of the vacuum gauge must be balanced, the inner diameter of the glass tube should be uniform and the top of the glass tube on one side should be closed, and a certain degree of vacuum should be maintained at all times. The tube is filled with working medium high purity mercury. The copper joint of the vacuum gauge is connected with the equipment under test. After the pressure in the equipment is exhausted by the vacuum pump, the absolute pressure can be directly read out by comparing the height difference of the mercury column end face in the glass tube of the vacuum meter with the scale plate (* the sum of the readings at both ends is the vacuum degree).

5、 Installation instructions:

If the vacuum gauge is installed vertically on the equipment, the user can buy ￠ 6.5mm copper pipe to weld with the copper pipe at the upper end of the vacuum gauge, and the other end to be welded with the vacuum valve. Please pay attention to the following matters when welding:

1. The temperature should not be too high to prevent the deformation of copper joint and affect the sealing performance.

2. The copper tube must be cleaned. Ether can be used if conditions permit, and oil cannot be used for cleaning.

3. Welding quality assurance, must weld two layers, absolutely can not leak.

4. The "O" ring should be removed carefully and evenly during installation.

When vacuumizing, the vacuum valve must be closed tightly, and the vacuum valve can be opened slowly after the vacuum pump is running, so as to prevent the mercury in the vacuum from being pumped out at once. When shutting down, the vacuum valve should also be closed to prevent the atmospheric pressure from entering the glass tube of the vacuum gauge and breaking the glass tube.

There are two screws to adjust the "0" position in the middle of the dial plate, which have been adjusted before delivery, so the user does not need to adjust it. When the "0" ring is disassembled, it is easy to replace the "0" ring.

6、 Maintenance and maintenance:

1. Please handle the vacuum gauge with care during transportation and use. Do not loosen the nut to prevent silver from flowing out.

2. The medium inside the true air meter - Mercury is specially treated and has a high purity. In the process of use, due to improper use and external factors, mercury deterioration and pollution will affect its accuracy, or even no reading. It should be sent to the manufacturer for repair, treatment and calibration before use.

3. After each use of the vacuum gauge, the valve must be closed to stop the vacuum pump, so as to prevent the vacuum pump oil from entering the vacuum system and the vacuum gauge.

4. The vacuum gauge will not be used in a short time, but can be stored in the inner diameter of the rubber plug.