Product Introduction
The Digital stiffness tester is a specialized instrument for measuring the bending resistance (stiffness) of paper and paperboard, designed according to the internationally accepted static bending method. The instrument is based on the static bending principle: bending the free end of a vertically clamped specimen, the resistance force when the specimen reaches a specific bending angle is the bending stiffness, expressed in mN; or the product of the resistance force and test length, expressed in mN·m. The stiffness test angle is 15° (adjustable 1-90°), crease test angle is 90° (adjustable 1-90°), with a range of 0-500 gf and display resolution of 0.001, capable of displaying in gram, mN, LB, OZ, and other units.

Key Features
Static Bending Method: Designed per the internationally accepted Two-Point Bending method, evaluating paper and board stiffness by measuring the resistance force when bending to a specified angle, providing standardized and comparable results.
Wide-Range Angle Setting: Both stiffness test angle and crease test angle are freely adjustable from 1-90°, flexibly adapting to testing requirements of different standards and product types.
High-Precision Measurement: Range of 0-500 gf, display resolution of 0.001, accuracy of 0.1% FS, ensuring fine discrimination and accurate repeatability of test results.
Multi-Unit Switching: Supports display in gram, mN, LB, OZ, and other units with one-touch switching, meeting different domestic and international standard and reporting conventions.
Color Touchscreen Control: Intuitive color touchscreen interface for easy operation; test time adjustable from 1-90 s with high automation.
Compact and Lightweight: Overall dimensions of only 390×410×260 mm and weighing just 4 kg, suitable for any lab bench with minimal space requirements.

Technical Specifications

FAQ
1. No display / screen off
Power not connected, blown fuse, or loose power cord. Check 220V supply; replace fuse with same rating; plug power cord securely.
2. Unstable digital display / jumping, won't zero
Sensor zero drift, instrument not level, or external vibration. Re-zero per manual; adjust leveling feet; move instrument to vibration-free area.
3. Buttons unresponsive / touchscreen failure
Aged buttons, touchscreen calibration offset, or system lag. Restart instrument; recalibrate touchscreen; check button wiring for looseness.
4. Test results too high (stiffness too large)
Specimen clamped too tight, specimen placed crooked, or swing angle set incorrectly. Adjust clamping force to standard value; place specimen centered; verify test angle specified in standard.
5. Test results too low (stiffness too small)
Specimen with creases/damage, worn knife edge, or pendulum not balanced. Replace with intact specimen; check and replace worn knife edge; recalibrate pendulum balance.
6. Poor data repeatability, fluctuating values
Inconsistent clamping position/force each time, temperature/humidity not equilibrated, or instrument not level. Standardize specimen position and clamping force; condition specimens at constant temperature/humidity for 4 hours; level instrument.
7. Pendulum not swinging or sticking
Dust on shaft, excessive damping, or foreign object jamming. Clean shaft and apply small amount of light oil; check damping device for sticking; remove foreign objects.
8. Clamping mechanism not holding / specimen slipping
Worn clamp jaws, insufficient pressure, or specimen slipping. Check clamp jaws for wear; adjust clamping pressure; ensure specimen clamped without skewing or looseness.
9. Auto-stop or error during test
Limit switch fault, swing angle exceeded set range, or program error. Check limit switch position; verify specimen within swing angle limit; restart and restore factory settings.

After-Sales Service
Thank you for your inquiry. Shandong Annimet Instrument Co., Ltd., established in 2007, has dedicated nearly two decades to the R&D, production, and sales of quality testing instruments. We regard product quality as the lifeblood of our enterprise and pursue excellence in every product developed. Annimet Instrument will consistently provide the tools for your ideas and creativity. Should you have any questions, please feel free to contact our customer service team.