Views: 222 Author: Leah Publish Time: 2025-03-27 Origin: Site
Content Menu
● Pre-Installation Requirements
● Mechanical Installation Process
>> Stage 2: Roller Integration
● Electrical System Configuration
● Advanced Calibration Methodology
>> Software Configuration Steps
>> Performance Validation Tests
>> Daily Checks
>> Issue 2: Negative Tension Values
● FAQ
>> 1. How does temperature affect MB25A calibration?
>> 2. Can I install two MB25A sensors in parallel?
>> 3. What causes signal drift over time?
>> 4. How to verify proper grounding?
>> 5. Is the MB25A suitable for metal webs?
The MB25A tension sensor delivers ±0.25% linearity for critical web tension control in printing, laminating, and converting operations. This guide incorporates advanced calibration protocols and field-proven installation techniques to maximize sensor performance.
Confirm the MB25A tension sensor kit includes:
- Stainless steel load cells (2) with IP65-rated housing
- Integrated roller shaft (1.5"/38mm diameter)
- Calibration certificate traceable to NIST standards
1. Clean mounting surfaces with isopropyl alcohol to remove oil/grease
2. Verify ambient temperature stability (±5°F/3°C per hour max variation)
3. Install surge protection on power lines if located near VFDs
- Lock out/tag out drive systems before installation
- Wear cut-resistant gloves when handling sensor edges
1. Mount the MB25A tension sensor using M12×1.75 bolts torqued to 47 N·m
2. Measure parallelism between sensor base and machine frame:
- Vertical tolerance: ≤0.003"/0.076mm
- Horizontal tolerance: ≤0.005"/0.127mm
Thermal Compensation
For installations with >50°F (28°C) temperature swings:
- Apply 0.015" (0.38mm) brass shims between dissimilar metals
- Leave 0.04" (1mm) expansion gap at floating bearing end
1. Slide the pre-loaded roller onto the MB25A tension sensor shaft
2. Secure shaft collars 2" (50mm) from each bearing block
3. Check rotational resistance:
- Acceptable: 0.5-1.5 lb-in (0.06-0.17 N·m)
- Excessive drag indicates misalignment
Critical Torque Values
| Fastener | Torque Spec |
|---|---|
| Bearing Housing Bolts | 35 N·m |
| Shaft Collar Screws | 20 N·m |
| Sensor Mounting Bolts | 47 N·m |
1. Route cables separately from power lines (minimum 12"/300mm spacing)
2. Ground shield wires at controller end only
3. Use star washers for reliable electrical contact
- Maintain excitation voltage between 5.8-6.2 VDC
- For long cable runs (>50ft/15m):
- Install 120Ω terminating resistor at controller
- Use 22AWG twisted pair cables
1. Configure input type as "Millivolt per Volt" (mV/V)
2. Set filter frequency based on web speed:
| Web Speed | Filter Setting |
|---|---|
| <100 fpm | 5 Hz |
| 100-500 fpm | 10 Hz |
| >500 fpm | 25 Hz |
1. Hang certified weights from calibration arm
2. Record output at 25%, 50%, 75%, and 100% capacity
3. Calculate linear regression coefficient (R⊃2; ≥0.9995 required)
1. Run known tension reference material through system
2. Compare MB25A tension sensor readings to reference values
3. Adjust span potentiometer if variance exceeds ±1%
1. Access calibration menu on Nexen TC-820 controller:
Menu Path: Setup > Sensors > Channel 1 > Calibrate
2. Enter calibration factors from sensor nameplate
3. Perform zero offset compensation with roller disengaged
| Test | Procedure | Pass Criteria |
|---|---|---|
| Zero Return | Remove load, wait 60s | ≤0.1% FS drift |
| Step Response | Apply 50% FS load rapidly | Settling time <2s |
| Temperature Drift | Cycle between 40-100°F | ≤0.02% FS/°F |
- Inspect for web debris accumulation
- Verify cooling fins remain unobstructed
- Re-torque mounting hardware to spec
- Clean slip rings with electrical contact cleaner
- Replace worn shaft collars
- Perform full NIST-traceable recalibration
- Probable Causes:
1. Loose shaft couplings
2. EMI interference from VFDs
3. Worn pillow block bearings
- Solutions:
1. Swap signal+/signal- wires at controller
2. Verify proper web wrap direction
- Diagnostic Steps:
1. Check for seized roller bearings
2. Confirm web tension <220 lb (100 kg) capacity
Proper implementation of the MB25A tension sensor requires meticulous attention to mechanical alignment, electrical integrity, and calibration rigor. By following these enhanced installation procedures and maintenance protocols, operators can maintain measurement accuracy within ±1% of full scale across the sensor's 10-million cycle service life.
The sensor features automatic temperature compensation from 32-122°F (0-50°C). For extreme environments, perform live web calibration at operating temperature.
Yes, for wide web applications. Synchronize controllers using Nexen's CANbus interface module (PN: NX-CAN-2).
Typically worn slip rings or cable insulation breakdown. Replace cables every 3 years in high-humidity environments.
Measure resistance between sensor body and ground point: ≤1Ω acceptable.
Yes, but reduce maximum tension by 15% when measuring high-stiffness materials like steel foil.
[1] https://www.nexengroup.com/media/gated_content/LitPDF/20127.pdf
[2] https://nireco.com/en/product/web/tensiton/mb-ts.html
[3] https://www.youtube.com/watch?v=otxMk3IZj64
[4] https://www.nexengroup.com/media/gated_content/LitPDF/MB.pdf
[5] https://www.fibossensor.com/how-to-troubleshoot-common-issues-with-a-sensor-tension.html
[6] https://www.vitess-industrial.ro/images/download/webcontrol/NEXEN_-_Tension_Control_Systems.pdf
[7] https://scienspec.com.tw/userfiles/file/mb-lvdt.pdf
[8] https://www.carotron.com/brch/lvdtwebro.pdf
[9] https://minplytech.com/products/mb-loadcell
[10] https://www.linkedin.com/pulse/how-install-tension-sensor-judy-zhu
[11] https://www.radwell.com/Buy/NEXEN%20GROUP/HORTON%20MANUFACTURING/911999
[12] https://www.contractorsdirect.com/products/multiquip-mb25a-rebar-bender
[13] https://www.instagram.com/rentalextampa/p/C-XiwcQKG__/
[14] https://www.nexengroup.com/913290-mb25a-sensor-tension-100-obs
[15] https://service.multiquip.com/pdfs/MB25A_Electrical_Function_Sequence.pdf
[16] https://www.nexengroup.com/911999-mb25a-sensor-tension-100
[17] https://www.sunbeltrentals.com/equipment-rental/concrete-and-masonry/rebar-bender-electric-rental/0320770/
[18] https://archive.org/stream/bitsavers_decfieldSeceTechnicalManualDec74_38830089/1974_Field_Service_Technical_Manual_Dec74_djvu.txt
[19] https://www.youtube.com/watch?v=2EERQP-Xvdo
