How to Calibrate an MS-1-100 100 lb S-Type Load Cell After Installation

pete8781
Jul 30
2 min read

MNM Scales: (832) 290-3120 • mnmscales@yahoo.com. Ask MNM for the exact MS-1-100 wiring/electrical data before connecting a replacement sensor to an existing indicator.

How to Calibrate an MS-1-100 100 lb S-Type Load Cell After Installation

A bare MS-1-100 load cell is not calibrated by itself with front-panel buttons. The connected indicator, transmitter or data-acquisition electronics store the scale factor and zero. Calibration therefore verifies the complete system: sensor, fixtures, cable, electronics and reference load.

1. Verify Wiring Before Powering the System

Confirm excitation and signal leads from the exact MS-1-100 documentation or MNM support. Do not assume wire colors match another MS-1 capacity. Check shield/ground treatment, connector pinout and strain relief. A reversed signal pair can produce negative weight; swapped excitation/signal wiring can create unstable or invalid readings.

2. Build an Axial, Free-Moving Fixture

Align the S-beam so force passes through its intended axis. Avoid bending, torque and side load. Rod ends, eye bolts or clevis hardware should articulate freely enough to prevent fixture misalignment from becoming measurement error.

3. Establish Unloaded Zero

With only the intended dead-load fixture attached, let the system stabilize and perform the indicator's zero calibration according to that indicator's manual. If the sensor output is unstable or will not settle, solve wiring/mechanical problems before span calibration.

4. Apply a Known Calibration Load

Apply a traceable known force in the same direction and fixture used in service. For a 100 lb sensor, practical reference loads are easier to manage than on very high-capacity cells, but the calibration rig must still be safe and aligned. Use the indicator's span procedure to associate the known force with the displayed value.

5. Verify Multiple Points

Check several points across the working range rather than only the span point. Repeat the same load to evaluate repeatability. Load and unload to observe hysteresis and return to zero. For tension/compression use, verify each direction only if the system is intended and safely fixtured for both directions.

After Replacing a Load Cell

Do not assume the old calibration remains valid. Even nominally identical sensors have output tolerances. After replacement, verify wiring, unloaded zero, span, repeatability and return to zero. If the scale is Legal-for-Trade, sealing and recertification requirements may apply.

Troubleshooting

No response: check excitation and open circuits. Negative response: check signal polarity and loading direction. Unstable reading: inspect shielding, cable, power, loose fixtures and side load. Poor return to zero: inspect binding or damaged/overloaded sensor. Correct at one point but wrong elsewhere: verify span, fixture linearity and whether the sensor/electronics are being used within their intended range.