Device Overview

1.1 Name and Model

Name: Digital Display Electric Lead Screw Testing Machine
Model: DYE-2000

1.2 Implementation Standard: Standard for Test Methods of Mechanical Properties of Ordinary Concrete

1.3 General Function Overview: This testing machine is used to determine the compressive strength of building materials such as bricks, stones, and concrete. The machine features electrically driven hydraulic loading, force measurement via sensors, digital display of force values, printer output of force data, and automatic calculation of compressive strength. Compliant with the national standard “Standard Test Methods for Mechanical Properties of Ordinary Concrete,” this machine requires manual control of the loading rate and is equipped with a loading rate indicator, peak hold function, and overload protection. It is an essential testing and inspection device for engineering institutions in fields such as construction, building materials, highways, and bridges.

Technical Specifications

Structural Overview

The testing machine consists of three main components: the main body, the hydraulic control box, and the force measuring instrument.

3.1 Body Section

The testing machine frame is composed of four vertical columns that connect the cylinder body to the upper beam. The upper crossbeam of the testing machine is equipped with an adjusting screw; by pressing “Screw Up” and “Screw Down,” the no‑load height of the testing machine can be adjusted.
The lower end of the leadscrew is fitted with a ball seat and an upper pressure plate. The lower pressure plate rests on the piston of the oil cylinder; when the specimen comes into contact with the upper pressure plate, the ball seat on the upper pressure plate automatically adjusts to maintain balance, ensuring that the specimen remains perfectly horizontal relative to the upper pressure plate. The lower pressure plate is engraved with positioning lines for the specimen—during testing, the specimen must be aligned precisely with these lines. A dust‑proof housing is installed beneath the lower pressure plate to prevent or minimize dust from entering the oil cylinder during piston movement, thereby avoiding damage to the cylinder body or the oil seals. A sealing device is installed between the piston and the oil cylinder to prevent oil leakage; however, if a small amount of oil does leak from the piston during use, an annular oil groove is provided at the top of the cylinder body, connected to an oil‑drainage channel that directs the leaked oil back to the main oil tank.

3.2 Hydraulic Control Section

The control box of this testing machine primarily consists of an oil tank, oil pump, oil filter, motor, speed valve, and return oil valve. The oil pump is a direct-drive, axial five‑column pump. When the testing machine is under load, the loading speed valve must be manually controlled to regulate the piston’s rising speed (this speed is integrated with the safety valve). To unload, simply turn the return oil valve, and the oil cylinder will slowly descend. The safety valve is pre‑adjusted to the appropriate position at the factory; users must not adjust the safety valve during normal operation.

Installation of the Testing Machine

4.1 When hoisting the testing machine, thread the lifting wire through the lifting ring screw at the top of the lead screw.
4.2 The testing machine shall be installed on a sturdy foundation approximately 20 cm above the ground, with two M16 anchor bolts pre‑embedded.
4.3 When installing the testing machine, use a 1/1000 frame level to measure the plane of the lower pressure plate and ensure that the lower pressure plate is perfectly horizontal. If it is not level, adjust it using shims (place shims under the nuts at the bottom of the upright columns).

Maintenance and Care

5.1 The testing machine shall be installed in a clean, dry environment with uniform temperature, free from vibrations and corrosive gas exposure.
5.2 The testing machine shall be kept clean, and parts on the upper surface of the testing machine that are not coated with a protective layer should be regularly oiled to prevent rust.
5.3 Use 46# anti-wear hydraulic oil.
5.4 The piston of the testing machine must not rise more than 30 mm. The control box of the testing machine is equipped with limit‑position calibration; when the arrow reaches the limit, the return oil valve should be immediately and slowly released to allow the piston to descend before restarting the motor for the next test.

Calibration of the Testing Machine

6.1 This testing machine shall be calibrated once a year.

6.2 The calibration of the testing machine shall be carried out under the following conditions:

(1) Within a temperature range of 20±10°C.

(2) In environments with relative humidity ≤ 80%.

(3) In a vibration‑free environment.

(4) The power supply voltage fluctuation shall not exceed ±10% of the rated voltage, and the voltage shall remain relatively stable.

6.3 After the instrument is powered on, allow it to preheat for 30 minutes, then adjust the zero point according to the operating instructions.

6.4 Start the motor, repeatedly apply load up to the maximum load three times, then reset the load display to zero and begin calibration.

6.5 This testing machine is only calibrated for relative error in indicated values and relative variability.