KMA36 universal magnetic encoder

KMT36 Rev 4

www.meas-spec.com

2012-july

13/16

MAGNETS AND SCALES

Rotational Mode

The KMA36 can be used with a magnet, preferably of disc or square shape or a magnet scale with pole

pitch 5mm.

For development purposes, MEAS offers a magnet disc made of plastic bonded Nd-Fe-B magnetic material

which provides an homogenous magnetic field with sufficient magnetic field strength for typical application

with the KMA36. The following table describes typical magnets parameters. Please refer to the website

information.

Symbol

Parameter

Condition

Min.

Typ.

Max.

Unit

Ø

Diameter

Neofer 48/60p only

14

mm

T

Thickness

Neofer 48/60p only

2.5

mm

Magnetic field strength

Neofer 48/60p only

540

mT

Operating temperature

Neofer 48/60p only

150

°C

Table 17a: Typical MEAS disc-magnet specification

Linear Mode

The linear mode of the KMA36 is designed for a magnetic scale with pole pitch 5mm. A magnetic scale is

made of a magnetic ferrite tape bonded on a steel support which guarantees mechanical stability. The steel

support is made of an optimum stainless steel alloy that provides no loss of magnetic field strength. MEAS

offers a standard scale with the following parameters for development purpose:

Symbol

Parameter

Condition

Min.

Typ.

Max.

Unit

Length

MEAS magnetic scale only

1

m

Pole length

MEAS magnetic scale only

5

mm

W

Width

MEAS magnetic scale only

10

mm

T

Thickness

MEAS magnetic scale only

1.3

mm

Δp

Accuracy

MEAS magnetic scale only

40

µm/m

Operating temperature

MEAS magnetic scale only

-40

100

°C

Table 17b: Typical MEAS magnet-scale specification

The correct magnet dimensions and assembly geometry depend on the specific arrangement of the

application and are part of the specification of the entire system.