Standard metal measure

1. Uses and features

　　The BJL series standard metal measuring device (hereinafter referred to as the standard measuring device) is a standard measuring instrument used to measure the volume of liquid and gas. It is a standard measuring device that must be equipped when measuring high-precision volume. It is widely used in the verification device of flow meter, and is one of the important equipment for performance test of flow meter in manufacturing and scientific research.

　　1. Purpose:

　　1) Calibrate the volume of the standard volume tube;

　　2) Verification of lower level standard gauges and working gauges;

　　3) Verify the measuring volume of various tank trucks, fuel dispensers, beer cans, etc.

　　2. Features:

　　1) High accuracy;

　　2) Made of 1Cr18Ni9Ti stainless steel plate, the inner wall will never rust;

　　3) The parts of the standard measuring device in contact with the medium are treated with a polishing process, and the amount of hanging water is small;

　　4) The standard measuring instrument has been treated with aging, and there is no deformation caused by residual stress, and the performance is stable;

　　5) Easy to use and maintain;

　　6) Before leaving the factory, each standard measuring device has been verified and certified by the national metrology department.

2. Main technical parameters

　　1. Measured medium: water, oil (gasoline, diesel, etc.), gas and other media;

　　2. Accuracy:

　　1) The first-class standard measuring device is: 5×10-5;

　　2) The second-class standard measuring device is: 2.5×10-4;

　　3) The third-class standard measuring device is: (0.5~1)×10-3.

　　3. Nominal volume (L): 10, 20, 50, 100, 200, 500, 1000;

　　4. Medium working temperature: 10℃~30℃;

　　5. Working conditions:

　　1) Ambient temperature: 5℃~40℃;

　　2) Relative humidity: 5%~95%;

　　3) Atmospheric pressure: 86kPa~106kPa;

　　6. Standard working conditions:

　　1) Ambient temperature: 20℃;

　　2) Relative humidity: 65%;

　　3) Atmospheric pressure: 101.325kPa.

3. Principle and structure

　　The volume of the standard gauge after being calibrated by the national metrology department is regarded as the "nominal volume", which is the volume of the standard gauge corresponding to the elevation of the standard gauge at 20°C. The nominal volume level is in the middle of the measuring neck. According to the enterprise standard Q/HQYB001-1998 "BJL Series Standard Metal Gauges", the indexing capacity on the measuring neck scale should be less than 5×10-5 of the nominal volume, and the standard The effective volume corresponding to the scale value of the neck of the measuring instrument is 2% of the nominal volume. The standard measuring device works according to the principle that the liquid level changes and the volume correspondingly changes. After the standard measuring device leaves the factory, there is a comparison table of liquid level elevation and volume. According to this table, the volume of the standard measuring device at 20°C corresponding to the elevation can be found.

　　The standard gauge is mainly composed of the following parts:

　　1. The main body of the measuring instrument:

　　The main body of the measuring device is the main part of the standard measuring device. It consists of a measuring neck, an upper cone, a lower cone and a middle part.

　　It is composed of a measuring cylinder and so on. The main body of the measuring device is made of 1Cr18Ni9Ti stainless steel plate. After the inner wall is polished, it is very smooth and has no unevenness defects. When the standard measuring device is measured, the residual amount of the medium is small, thus ensuring the measuring accuracy of the standard measuring device. The volume from the drain valve at the bottom of the standard measuring device to the liquid level of the measuring neck is the measuring volume of the standard measuring device.

　　2. Bracket:

　　The bracket is welded by A3F flat steel pipe or channel steel to support the main body of the measuring device. At the bottom of the bracket is equipped with three mountable,

　　The down-adjusting leveling bolt is used to adjust the standard gauge to be in a horizontal position when it is working.

　　3. Thermometer:

　　The thermometer is installed on the upper cone of the measuring device to measure the temperature of the standard measuring device and the medium.

Four. Dimensions

　　The dimensions are shown in Table 1:

　　Table 1 External Dimensions of Standard Measuring Instruments

five.        Use and maintenance of standard metal gauges

1. use:

When using, adjust the leveling bolt first, and adjust the standard gauge to the level by observing the level gauge (provided by the user).

In the formula: V _t ——the actual volume of the metering medium at _t ℃;

      V _B ——the standard measuring instrument corresponding to the elevation at 20℃, that is, the scale volume of the standard measuring instrument;

      b ₁ ——The volume expansion coefficient of the standard measuring instrument material, b ₁ =50×10 ^-5 ℃ ^-1 ;

      t——The temperature of the measuring medium.

2. maintain:

1) After the standard measuring instrument leaves the factory, the reading scale shall not be adjusted without authorization, and the connecting flange of the measuring instrument body and the bracket shall not be

Self-disassembly, such as adjustment and disassembly, should be re-calibrated before use;

2) Do not block the vent hole on the upper part of the glass tube level gauge;

3) During transportation and use, do not forcefully collide with the main body of the standard gauge. After the collision is deformed, it should be re-calibrated

Can be used later;

4) When using different media, clean the inner wall of the standard measuring instrument to ensure that the volume indication and accuracy are different.

Change;

5) Objects with oily dirt, screws, nuts, etc. shall not fall into the standard measuring device, so as not to lower the standard measuring device.

The roughness of the wall and the accuracy of the standard gauge.

six. Supply complete set

     When the standard measuring device leaves the factory, a mercury thermometer is attached. The specifications are: the minimum graduation is 0.1°C, the range is 0-50°C, and a comparison table of elevation and volume is attached.

seven. download Google

Please specify when ordering:

1) Volume of standard measuring device;

2) The name, viscosity, density, temperature range and corrosivity of the measuring medium;

3) Measurement accuracy;

4) Special requirements and other instructions.