Magnetic position sensors Piher for extreme conditions

Thanks to its many years of experience, Piher is an expert in advanced position sensing technologies. Their products allow us to precisely measure and control rotary and linear motion. The introductory article about the contactless magnetic position and rotation angle sensors by the Piher brand that you can now find in our stock offer was prepared by Miroslav Piskor, product specialist from SOS electronic.

Principle of operation

Piher sensors use an IC with four Hall elements and an integrated magnetic concentrator (IMC) that bends and concentrates the magnetic flux density in the x and y axes, Bx and By, in the z-axis direction.

The magnetic flux density Bx is proportional to Vx, where:

Vx = V_hs1 - V_hs2 = k1*(B_hs1_⟂ - B_hs1_z) - k1*(-B_hs2_⟂ - B_hs1_z) = k1*(B_hs1_⟂ + B_hs2_⟂) = k2*Bx, where:

• V_hs1, V_hs2: output voltage of the Hall elements HS1 and HS2
• B_hs1_⟂, B_hs2_⟂: magnetic flux densities created by IMC from Bx
• B_hs1_z, B_hs2_z: magnetic flux densities Bz

Similarly, By is proportional to Vy = V_hs3-V_hs4. Thus, the sensor is only sensitive to the magnetic flux density coplanar with the surface of the IC. The rotation angle is calculated from the vector components Bx and By of the magnetic flux density.

Contactless position sensors by Piher

Piher contactless magnetic sensors measure the rotational angle or linear position and use on-axis or off-axis sensing methods.

1. In an on-axis sensing method, the integrated circuit is placed under a diametrically magnetized magnet at the end of the shaft. 

2. In the off-axis sensing method, the IC is placed next to a diametrically magnetized magnet through which the shaft passes.

3. The 2-pieces rotation angle sensor PS2P-CON uses in-axis sensing. The magnet is attached to the rotating part and the sensor is attached to the steady part or vice versa.

4. The 2-piece linear position sensor PSP2-LIN uses off-axis sensing. The magnet is attached to the linearly moving part and the sensor to the steady part or vice versa.

You can find an overview of the Piher contactless position sensors in the product guide. 

Features and benefits of Piher non-contact position sensors:

• Linearity: ± 1 % absolute (0.5 % upon request)
• Simple and robust magnetic design
• High resistance to vibration, moisture and dust ingress, IP67, IP69K for selected series
• Programmable rotation angle measurement range up to 360 degrees (without dead band)
• Programmable linear transfer characteristic
• Optional analog (ratiometric) PWM serial protocol
• Programmable switch output
• Up to 14-bit angular resolution
• Fully redundant option
• Self-diagnostic features
• Lifetime of 50 million rotation cycles (depending on application and mounting), virtually unlimited life for 2-piece rotary and linear sensors
• Operating temperature: - 40 to + 150 ˚ C

Piher position sensors in practice:

• Automotive industry
• Agriculture
• Construction industry
• Handling technology – forklifts 
• Industrial automation
• Healthcare
• Navy

The selected magnetic position sensors that we have included in our assortment are available directly in our warehouse, we will be happy to provide you with the rest on order.