MLB-300CD type extensometer calibrator

The MLB-300CD extensometer calibrator is a purely mechanical high-precision displacement micrometer instrument. According to the requirements of JJG762-92 extensometer calibration regulations, it is specifically used for the calibration of various extensometers, and is also widely used for the calibration of displacement sensors and corresponding dial gauges and micrometers.

Structural characteristics and reading methods

1. This instrument consists of a precision differential probe and a measuring bracket. The calibration device is designed with a modular structure. By combining precision differential probes and support arms in various ways or positions, and equipped with extended column attachments, as well as various forms of separated samples such as cylinders, plates, and blades, it is easy to calibrate various specifications and models of extensometers. Users can also configure specialized accessories for precise micro deformation measurement according to their specific testing needs.

2. The precision differential probe consists of a sliding measuring rod, a measuring rod sleeve, and a reading deviceComposed of a cylinder, a reading outer cylinder, and a high-precision threaded pair. Its maximum range is 30mm;Minimum division (cursor division) 0.0002mm; Rotate the outer cylinder with a division of 0.002mm.

The displacement change reading is:

L=（a+0.001b+0.0001c）-(a0+0.001b0+0.001c0)

Among them: a - Reading of millimeter markings on the inner cylinder

B - Reading of engraved lines on the outer cylinder

C - cursor marking reading

A0, b0, c0 are the readings before the corresponding displacement changes

Precision differential cylinder

2、 Various technical accuracy indicators

1. Measuring extensometer gauge range Lmax 500mm

2. Measure the installation aperture of the support arm on the support with a diameter of 10; φ28

3. Differential probe reading inner cylinder axial scale 0.5mm/grid

4. Differential probe reading inner cylinder vernier scale 0.0002mm/grid

5. Differential probe reading outer cylinder circumference scale 0.002mm/grid

6. Precision index of high-precision differential probe

Calibration instrument indication error:

Range within 0.5mm ≤ 0.5 μ m Absolute error

Range above 0.5mm ≤ 0.10% Point by point relative error

Reference standard:

JJF1096-2002 Calibration specification for extensometer calibrator

ISO9513:1999 Calibration of extensometers for uniaxial testing of metallic materials

JJG762-1992 Verification Regulations for Stretchers

Can calibrate a 0.5-level extensometer

3、 Instructions for use

Please calibrate the extensometer according to the requirements of JJG762-92 extensometer calibration regulations:

1. Select a separated sample that is essentially identical to the test sample based on the specifications and model of the tested extensometer and the specifications of the test sample.

2. Adjust the position of the two measuring arms to obtain a suitable calibration space; Adjust the position of the eccentric snap spring on the two measuring arms to ensure that the two separated samples are coaxial; Adjust the distance between the micrometer head and the lower base to ensure the effective travel of the micrometer head. After all adjustments are made, pay attention to tightening all required fastening parts. During the verification process, except for the parts that allow for movement displacement, no sliding or loosening is allowed.

3. Selection and testing of the calibration range and detection points for extensometers:

(1) The scope of verification should be determined based on the technical parameters of the material to be tested by the extensometer. For example, if using a 50mm gauge length extensometer to test the σ P0.2 technical data of a steel sample, please choose a calibration range of 1mm. If measuring the value of n, a calibration range of 25mm is required.

(2) The selection of inspection points is generally not less than 8 points per range. For the above selected examples within a 1mm calibration range, it is best to calibrate 10 points, that is, one point every 0.1mm.

(3) When verifying the extensometer, always use the integer scale multiplication method. Do not use a vernier to estimate the reading or decimal digit reading, as each ten point reading has caused reading fatigue. Estimate the reading or decimal digit reading.

Reading will exacerbate the generation of measurement errors. The integer single line reading method is the clearest, simplest, and most accurate, with the lowest probability of error. Even if it occurs, it will be detected in a timely manner because the error of the extensometer will increase exponentially due to the reading error of the integer scale. This gross error will be quickly detected in a timely manner.

4. The use of extended columns: When using the basic column to calibrate the extensometer and cannot guarantee the gauge space of the extensometer, remove the protective cap on the basic column, insert the extended column into the main column and align it with the V-shaped groove, and tighten the screw. It must be securely fastened before use.

4、 Comes with measuring accessories along with this instrument

1. Combine 2 calibration rods. Used for combining multiple simulated separation samples.

2. 4 blades. Installed on a combination calibration rod: used for COD or JIC clamp gauge calibration.

3. Two horizontal test pieces. Installed on a combination calibration rod: used for the calibration of transverse extensometers.

4. Two pieces of board. Installed on a combination calibration rod: used for simulating the calibration of plate samples.

5. 1 piece of rod with a diameter of 10 × 100. Placed in the spring hole of the upper support arm for simulating the calibration of samples with a diameter of 10mm or more.

6. 1 piece of rod with a diameter of 10 × 50. Placed inside the micrometer head connection sleeve for simulating the calibration of samples with a diameter of 10mm or more.

7. One variable diameter rod with a diameter of 10/5 × 100. Placed in the spring hole of the upper support arm for simulating the calibration of samples with diameters below 5mm.

8. One variable diameter rod with a diameter of 10/5 × 50. Placed in the spring hole of the upper support arm for simulating the calibration of samples with diameters below 5mm.

9. One 170mm extended column. Used to extend the height of the calibration instrument.

10. One connecting sleeve. Place it on the end of the differential measuring head sliding rod with a diameter of 10, and connect the separated sample for verification.

11. For the convenience of debugging and installation, the instrument is equipped with one No. 14 wrench, one No. 3 hex wrench, one Phillips screwdriver, and one Phillips screwdriver.

Measurement attachments

5、 Maintenance and upkeep

1. When disassembling and assembling the upper and lower support arms, it is necessary to prevent the positioning nails or steel balls from falling off. If the clamping clip is too tight, it is only allowed to use screws to push it open.

2. The precision of the differential head has been calibrated before leaving the factory, and it cannot be disassembled by oneself during use.

3. It should be used in a clean and dust-free environment, and attention should be paid to keeping the instrument clean and dust-free at all times.

4. Be careful to prevent external damage and rusting.

5. Regularly submit to relevant metrology departments for re inspection.