1.1 Instrument Usage

The ST2722 automatic powder resistivity tester is a measuring instrument that uses the four-terminal method to test the "resistivity - pressure" characteristic curve of powder. It can also be used as a tablet press and can be expanded into a compaction density tester.

This instrument is suitable for graphite carbon plants, coking plants, powder metallurgy plants, colleges and universities, research institutes, metrology units, industrial and mining enterprises, etc. It is an important and excellent tool for testing and analyzing the resistivity parameters of powder samples.

1.2 Adopt the main national standards

Four-terminal method: GB/T 24521-2018 "Method for Determination of Resistivity of Carbon Raw Materials and Coke" and YS/T 587.6-2006 "Test Method for calcined Petroleum coke for Carbon Anodes - Part 6: Determination of Resistivity of powder"

"GBT 40007-2021 Nanomaterials - Contact Measurement Method for Resistivity of Nanomaterials - General Rules" (Participated in the formulation)

1.3 Instrument Composition

The main components of the entire set of instruments include: the measurement and control host, the automatic pressure control console, the automatic height sensor, the feeder, the four-probe electrode, and the corresponding PC measurement and control software modules, etc.

The measurement and control host is the core part of the entire system for electrical control, measurement, display, communication, etc. It is mainly composed of a precision multi-range constant current source, a wide-range high-precision voltmeter, a color LCD display module, a digital keyboard input control module, a USB communication module, and an embedded single-chip microcomputer system unit.

The automatic pressure control console is used to automatically control the application of pressure according to the system pressure setting requirements. It is mainly composed of an electric press, pressure detection and control modules.

The automatic height sensor is used for the automatic synchronous detection of the thickness of powder samples.

The feeder is used for adding powder samples. Split type, multiple specifications, convenient for multi-purpose selection and operation.

The four-probe electrode is used to apply current and test voltage on the tablet powder in accordance with the four-probe method.

PC measurement and control software is used to achieve measurement and control of instruments, as well as functions such as data viewing, editing, saving, printing, and historical query on the PC end.

Ii. Technical Parameters

2.1. Measurement range and resolution

Resistivity: 15.0×10-6 to 200.0×10 3 Ω-cm Resolution: 1.5×10-6 to 0.1×10 3 Ω-cm

(1.0×10-6 to 200.0×101 Ω-cm resolution 0.1×10-6 to 0.1×101 Ω-cm)

2.2. Measure the material

All kinds of powders.

2.3. Range classification and error grades

Full display	200.0	20.00	2.000	200.0	20.00	2.000	200.0	20.00
Maximum extended range:?	?KΩ-cm	?	?	Ω-cm	?	?	mΩ-cm	?
Basic error:?	±2% reading: ±4 digits	±1.5% reading: ±4 digits	±0.5% reading:±2 digits	?	?	?	±0.5% reading:±4 characters	?	?	?	?

2.4. Digital Voltmeter:

⑴ Range: 10mV to 100mV, automatic

⑵ Display :4 significant figures, with a maximum display of 200.0. Decimal points and units are automatically displayed

2.5. Numerical control constant current source

Current output: Adjustable DC current ranging from 0.1μA to 1000mA, with automatic step adjustment by the system.

2.6. Partial parameters of the powder test bench:

1. Sample particle size: It is recommended to be below 40 mesh, with a maximum particle size not exceeding 10 mesh. Fine particle size has no effect!

2. Sample container: Inner diameter: Φ11.28mm (S=1.0cm 2

Height: Adjustable from 0 to 20mm, with height sensor monitoring, measurement error: ±0.05mm.

3. Pressure range: Maximum 30Mpa, continuously adjustable from 0 to 30 mpa.

4. The pressure mechanism adopts manual operation, and the pressure is stable and adjustable.

The electronic digital display shows the pressure value, with four-digit effective display values ranging from 00.00 to 30.00MPa, and the accuracy is ±0.01 MPa.

5. Test bench shape: 250mm (front width) × 220mm (rear length) ×540mm (total height)

Weight: 10Kg

2.7. Power Supply:

Power consumption: Less than 100,000

Input :220V±10%, 50Hz

2.8. The working conditions of this instrument are:

Temperature: 0-40℃

Relative humidity: ≤60%

There should be no strong electromagnetic field interference in the studio, and it should not share power supply with high-frequency equipment.