Practical Technical Guide for Sanfeng SJ220 Roughness Tester

Sanfeng SJ220 is a portable and practical small surface roughness measuring instrument, which relies on touch screen operation, multi scene adaptation, and ultra long battery life advantages,
Widely used in production sites and laboratories. This article extracts key technical points from core parameters, operation calibration, maintenance, and troubleshooting to assist users in efficiently using the instrument.

1、 Core technical parameters and advantages

SJ220 adopts needle tracing method for measurement, with a Ra measurement range of 0.025-12.5 μ m and a Z1 axis range of 360 μ m,
The X-axis measurement length is divided into two specifications: 17.5mm (standard/retreat drive) and 5.6mm (lateral drive); Equipped with two force gauges of 0.75mN and 4mN, suitable for workpieces of different hardness;
Indication error ± (5%+4nm), measurement repeatability ± 3%, resolution up to 0.001 μ m, supports multi parameter measurements such as Ra, Rz, Rt, and multiple filtering methods, compatible with ISO21920 standard.

The core advantages of the product are outstanding: a 2.8-inch touch screen with HOME physical keys, which can be operated even with gloves; The built-in lithium battery can complete about 1000 measurements when fully charged,
No memory effect, can be charged at any time; Supports bidirectional data transmission via USB and Bluetooth to meet the requirements of paperless operations; Can be paired with measuring platforms or extension rods to adapt to complex workpiece measurements.

2、 Standard Operating and Calibration Procedures

1. Basic measurement steps

1. Power on preparation: Turn the battery switch to ON, press and hold the POWER button to start, and confirm that the 6V DC adapter is securely connected to the external power supply;

2. Parameter setting: Select the measurement mode through the touch screen or HOME button, set the sampling length (0.08/0.25/0.8/2.5mm), evaluation length (1L-5L), and filtering method, and match the workpiece to select the force measurement specification;

3. Workpiece placement: Clean the oil and impurities on the surface of the workpiece, ensure a stable fit with the measuring platform, and ensure that the cutting pattern is perpendicular to the measuring direction of the detector;

4. Perform measurement: Gently place the sensor to the measurement starting position, press the START button after the stylus is attached to the workpiece, and after completion, data can be stored or transmitted.

2. Key calibration steps

Calibration should be performed after the new machine is activated, the detector is replaced, the accuracy is abnormal, or regular maintenance is carried out: enter the "Calibration Measurement" interface and enter the calibration value of the standard sample block;
Place the instrument steadily on the sample block to ensure normal contact of the detector; Press the START button to complete the measurement, check the deviation between the calibration value and the standard value, and if it is within the allowable range, the calibration is valid.

3、 Daily maintenance and upkeep standards

Daily maintenance:
Use a soft brush to clean the contact pins, guide rails, and platform dust and iron filings, and if necessary, wipe them with anhydrous ethanol;
Check the battery level and charge it promptly if it is low (about 2.5 hours to fully charge); Avoid using instruments in dusty, humid, and high-temperature environments.

Regular maintenance:
Check the tension of the drive belt every week and apply special lubricating grease to the guide rail; Verify accuracy with standard samples every month, clean USB and power interfaces to prevent oxidation;
Check the battery life every six months, replace the original battery after aging, and recommend professional personnel to clean the internal dust accumulation; Long term disuse requires fully charging and shutting down, applying rust proof grease, and storing in a dry and ventilated place.

4、 Typical fault diagnosis and maintenance

1. Unable to power on/abnormal power supply: Check the output of the power adapter or replace the power cord; Replace the original battery if the battery is aging; The fuse needs to be replaced with original accessories of 250V and 5A specifications if it is blown.

2. Measurement without induction/red induction strip: often caused by collision. Remove the measuring needle, disassemble the drive part, and correct the offset transmission components; Clean the sensor sensing area, replace worn contact pins with diamond models of the same specifications, and calibrate and verify after reinstallation.

3. Large measurement error/unstable data: Clean or replace worn contact pins, confirm that the workpiece is placed steadily and the measurement direction is correct; Re calibrate the instrument and verify if the filtering method and sampling length settings match the workpiece.

4. Touch screen/button malfunction: Clean the oil stains on the surface of the touch screen; Button contact oxidation requires module replacement; Flower screen or black screen are mostly caused by circuit board faults. Contact professional personnel for repair.

5. Data transmission failure: Check if the connection cable is damaged and if the interface is clean; Bluetooth connection must ensure successful pairing and no interference; The PC side needs to install dedicated Data View software and match the communication protocol.

Attention should be paid when using, it is strictly prohibited to press the sensor or stylus, and the workpiece or instrument should not be moved during measurement; Original accessories must be used. Do not disassemble complex faults by yourself. Contact professional personnel for handling, which can effectively extend the service life of the instrument and ensure measurement accuracy.