4. Key Points for S-Type Load Cell Selection

4.1 Capacity Selection – “Better slightly larger than too small”, but within reason

Capacity is the most fundamental and error-prone step in selection. If the capacity is too small, impact forces can permanently deform or even destroy the elastic body. If it is too large, the output signal becomes weak, resolution drops, and accuracy cannot meet requirements. 

The scientific approach is: choose a capacity 1.2–1.5 times the actual peak force, and it is recommended to keep the daily working load within 30%–70% of the sensor’s rated capacity. If dynamic factors such as shock, vibration, or rapid loading are present, use a dynamic coefficient of 1.3–1.5. 

Typical example: If the maximum force on the equipment is about 70kg, choose a 100kg sensor, leaving about 30% safety margin.

  4.2 Environmental Factors – Material and Protection Rating

 S-type load cells are often used in industrial environments, where conditions directly affect long-term stability and lifespan.

 Humid or corrosive environments: Must use stainless steel sensors for better corrosion resistance. Naturoll’s S-type models such as NF301, NF302, and NF303 are made of stainless steel and meet the requirements for harsh conditions.

Dusty or wet environments: Pay attention to the ingress protection (IP) rating. IP65 or higher is generally recommended for industrial environments. Some Naturoll models, such as NF201, have already achieved IP65.

Temperature fluctuations: Large temperature variations can cause zero drift; check the sensor’s operating temperature range.

 4.3 Installation – Force direction is critical

 S-type sensors are suitable for bidirectional measurement, but with the prerequisite that the force must be applied strictly along the sensor’s main axis, avoiding side loads, bending moments, or torque. 

Use spherical washers, spherical rod end bearings, or flange adapters to automatically compensate for installation misalignment and prevent eccentric loading. For S-type sensors with threaded ends like the NF302, ensure that the force axis coincides with the sensor’s centerline when installed in series. 

4.4 Accuracy Class – Choose according to needs, not blindly pursue the highest

Trade settlement or high-precision testing: Requires C3 or higher accuracy class.

General industrial process control: C2 or industrial grade (0.03–0.05% FS) is sufficient and offers better cost-effectiveness.

Special applications: The NF303 is positioned as a high-precision model, suitable for precision mechanical testing.

 4.5 Output Signal – Match the back-end system

Naturoll’s S-type sensors typically have an analog voltage output sensitivity of 2.0±10% mV/V. They require an amplifier, transmitter, or data acquisition system to interface with a PLC or controller. During selection, confirm that the input range of the back-end equipment matches the sensor’s output range. 

5. Pitfalls to Avoid 

The following mistakes are common – keep this list for reference: 

Myth 1: Larger capacity is always safer

In fact, an excessively large capacity will result in a weak output signal for small forces, and after adding system noise, accuracy drops significantly. This is like “using a sledgehammer to crack a nut” – and you still won’t measure accurately.

 Myth 2: Ignoring shock and dynamic loads 

Many engineers select based only on static force, only to have the sensor damaged by impact forces on startup. Always multiply by a dynamic coefficient of 1.3–1.5.

 Myth 3: Ignoring side loads and eccentric forces 

Although S-type sensors have good resistance to eccentric loading, improper installation (misalignment or side forces) can still cause measurement errors or damage.

 Myth 4: Introducing pre-tension during installation 

Applying additional force to the sensor during installation will cause zero-point offset and inaccurate measurements.

 6. Quick Selection Checklist 

When selecting an S-type load cell, go through the following items in order: 

1. Capacity confirmation: What is the peak force? What dynamic impact coefficient is needed? Leave about 30% margin.

2. Installation space: Is there enough space for in-line installation? Is a micro model (e.g., NF302) required?

3. Type of force: Tension, compression, or both? S-type supports both.

4. Environmental conditions: Temperature range, humidity, presence of corrosive gases/liquids? Is stainless steel required?

5. Accuracy requirements: For trade settlement, precision testing, or general process control?

6. Protection rating: Does the dusty/wet environment require IP65 or higher?

7. Output and system compatibility: Does the back-end acquisition equipment’s input range match the 2.0 mV/V output of the sensor? 

7. Conclusion 

Naturoll’s S-type force sensor product line is rich, with capacities covering from 200g to 2000N. The stainless steel construction and high-precision characteristics enable them to handle everything from micro-force testing to industrial automation force measurement. 

The essence of selection can be summed up in one sentence: Choose the right capacity with margin, match material to environment, ensure axial alignment, and select accuracy as needed without waste. 

Correct selection is the foundation of an efficient and reliable automated production line. If you have further questions about specific applications of Naturoll S-type sensors, please visit Naturoll’s official website (https://www.naturollsensor.com/) for more product details and technical support.