ALF209 Donut Ring Force Sensor

Ideally suited to engineering force measurements where overall height is restricted

About the ALF209 Donut Ring Force Sensor

The ALF209 is ideally suited to engineering force measurements including through centre safety testing of cables, rods and bolts. It is designed for easy installation, usually between two flat faces bearing on its loading rings, either unattached or with retaining spigots positioned in the centre hole. Alternatively tensile load transfer can be achieved via a tie rod assembly through the centre hole. In this way the loadcell can indirectly measure tensile loads in a “fail-safe” mode.

We are happy to design variants of this loadcell to meet your specific requirements.
Please consult our engineering department.

Geometry: Axial strain cylinder in a sealed case, with raised end load bearing faces and hole right through. For use in compression or in fail-safe tensile applications.

Features ALF209

  • Full load range: 1MN, 2MN, 4MN
  • Non-lin./hysteresis: 1.0/1.0% RL
  • Hardened stainless steel body
  • Very high structural load limit

The loadcell is fitted with 2 metres of PVC insulated 4 core screened cable type 16-2-4C or a 4 pin Binder
723 series chassis plug.

  • Excitation + = Red or pin 1 Signal + = Yellow or pin 3 Screen = Orange
  • Excitation - = Blue or pin 2 Signal - = Green or pin 4

The screen is not connected to the loadcell body.


Measurement range
1MN, 2MN, 4MN
Non-linearity - Terminal
±1.0% RL
±1.0% RL
Creep - 20 minutes
±0.1% AL
±0.02% RL
Rated output - Nominal
Rated output - Rationalised (1000 and 2000kN)
Force direction
Rationalisation tolerance
±0.5% RL
Zero load output
±4% RL
Temperature effect on rated output per °C
±0.005% AL
Temperature effect on zero load output per °C
±0.03% RL
Temperature range - Compensated
-10 to +50°C
Temperature range - Safe
-10 to +80°C
Excitation voltage - Recommended
Excitation voltage - Maximum
Bridge resistance
350 Ω
Insulation resistance - Minimum at 50Vdc
500 MΩ
Overload - Safe
50% RL
Overload - Ultimate
400% RL
Weight - Nominal (excluding cable)
7 to 9kg
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