HSP-540 concrete shrinkage expansion meter

1、 Main purpose

The HSP-540 concrete shrinkage and expansion meter complies with the provisions of GBJ82-85 and is an instrument used to measure the length (volume) changes of concrete specimens during the hardening process under certain environmental conditions. It can provide excellent basis for research, education, quality control, and testing of the characteristics of concrete by building technology research institutes, education departments, design and construction units.

2、 Technical parameters

1. Measurement range 534-545mm

2. Test piece size: 100 * 100 * 515

150*150*515

3. Standard rod length: 540 ± 0.2mm

4. Range of dial gauge: 0-10mm

Small scale value of dial gauge: 0.01mm

5. Dimensions (length x width x height): 670 x 240 x 180mm

6. Quality ≈ 13Kg

3、 Structure and Function

This instrument consists of a base, positioning column, adjustable column, dial gauge, standard rod, etc.

1. The base is a steel structural component used for installing and connecting other parts. The two 20mm wide smooth planes in the middle of the upper part are the reference surfaces of this instrument, used for placing concrete test blocks.

2. Positioning column, used for longitudinal and transverse limit of the left end of the standard pole and concrete test block measuring head.

3. Adjustable column, with three pre fabricated through holes for installing dial gauges and fastening screws to assist in the positioning of the dial gauges. Three through holes are located 50mm, 75mm, and 100mm away from the base reference surface. A hole 50mm away from the base reference plane is used to measure concrete test blocks with specifications of 100 * 100 * 515; A hole 75mm away from the base reference plane is used to measure concrete test blocks with a size of 150 * 150 * 515 (as the test mold size is only 150 * 150 * 600, it is recommended to use a shortened test mold to make the formed size of the concrete test block 150 * 150 * 515).

4. The standard rod serves as the reference length for the instrument. The standard pole has been installed on the standard pole rack before leaving the factory. Please do not disassemble or assemble it at will to avoid affecting the accuracy of the center height of the standard pole. The letters "50", "75", and "100" on each side of the standard pole indicate that if placed on the base reference plane, the center heights of the standard pole are 50mm, 75mm, and 100mm, respectively.

4、 Operation and usage

1. Select the desired center height of the standard rod, place the left end of the standard rod against the groove of the positioning column, and ensure that the lower plane of the standard rod bracket is tightly attached to the reference surface of the base. Then slowly push the other end of the standard rod into the center of the instrument.

2. Loosen the set screw and slowly insert the dial gauge into the adjustable column hole of your choice, so that the dial gauge probe contacts the right end of the standard rod. Then tighten the set screw to position the dial gauge on the instrument. Read and remember the scale of the dial indicator at this moment.

3. The installation method of concrete specimens is the same as 1.

4. The production, curing, shrinkage, and expansion tests of concrete specimens shall be conducted in accordance with relevant standards such as GBJ82-85.

5、 Precautions

1. The instrument should be placed on a flat workbench, and its four feet should be evenly stressed. Avoid three-point force to prevent deformation of the instrument and affect accuracy.

2. The standard rod is the reference length unit of the instrument and needs to be handled gently to prevent deformation.

3. The dial gauge is a delicate component, and the test piece should be placed and removed gently and carefully, without colliding with the gauge frame and stem.

4. After each use, a small amount of lubricating oil should be applied to the surface of non painted parts, and instrument oil should be applied to the surface of the moving parts of the dial gauge.

5. Dust prevention measures should be taken in environments with high dust concentration or long-term shutdown.