BML-S _ B/C/E0-Q _ _ _ -M4 _ _ - _ 0-KA _ _ /KA _ _-S284
Incremental Magnetic Linear Encoder
7
System selection (continued)
7.2
Additional parameters for rotative
applications
The BML linear encoder enables precise adjustment to the
respective application with the rotative magnetic tapes
(magnetic rings).
Definition of impulses per rotation
The number of required impulses per rotation varies
depending on the application. It defines the resolution of
the sensor head and the magnetic ring diameter.
BML-S2B/E...
Impulses/rotation with 4x evaluation
Ø exterior magnetic ring
Resolution
31 mm
49 mm
Number of poles (with 5 mm pole width)
20
32
F 5 μm
20,000
32,000
G 10 μm
10,000
16,000
H 25 μm
4,000
6,400
K 50 μm
2,000
3,200
Tab. 7-3:
BML-S2B/E...: selection aid for magnetic rings
BML-S1C...
Impulses/rotation with 4x evaluation
Ø exterior magnetic ring
Resolution
31 mm
49 mm
Number of poles (with 5 mm pole width)
20
32
L 100 μm
1,000
1600
M 200 μm
500
800
N 500 μm
200
320
P 1000 μm
100
160
R 2000 μm
50
80
Tab. 7-4:
BML-S1C...: selection aid for magnetic rings
Maximum speed
The BML system enables recording of rotative movements.
The speed and magnetic ring diameter determine the
speed of the ring on the sensor head.
The selection of the resolution and edge distance of the
sensor head determines the maximum movement speed
that the sensor can detect. This results in a maximum
speed in accordance with the following formula:
60 × max. movement speed [m/s]
Max. speed [min
] =
–1
π × magnetic ring diameter [m]
www.balluff.com
72 mm 75.4 mm 122 mm
46
48
78
46,000
48,000
78,000
23,000
24,000
39,000
9,200
9,600
15,600
4,600
4,800
7,800
72 mm 75.4 mm 122 mm
46
48
78
2300
2400
3900
1150
1200
1950
460
480
780
230
240
390
115
120
195
Maximum movement speed and minimum edge distance,
see Tab. 7-1 und Tab. 7-2 on page 16.
Recommendation: max. speed 10% less than the
detected speed value.
Max.
movement
speed
31 mm
49 mm
20 m/s
12322
7795
14.75 m/s
9087
5749
10 m/s
6161
3898
8.8 m/s
5422
3430
8 m/s
4929
3118
7.7 m/s
4744
3001
6.5 m/s
4005
2533
5 m/s
3080
1949
4.2 m/s
2588
1637
3.95 m/s
2434
1540
1267
3.25 m/s
2002
3 m/s
1848
1169
1.8 m/s
1109
702
1.7 m/s
1047
663
1.5 m/s
924
585
0.95 m/s
585
370
0.9 m/s
554
351
0.75 m/s
462
292
0.65 m/s
400
253
0.395 m/s
243
154
0.375 m/s
231
146
0.26 m/s
160
101
0.195 m/s
120
0.13 m/s
80
See example below
1)
Tab. 7-5:
Maximum speed of rotative magnetic tape (magnetic ring)
Example:
BML-S2B... sensor head with 5 µm (F) resolution and a
min. edge distance of 1 µs (G).
Tab. 7-1 on page 16 produces a max. movement speed of
3.25 m/s for this sensor head. With a magnetic ring
diameter of 49 mm = 0.049 m, a speed of 1267 rpm can
be achieved with this formula (the value can also be read in
Tab. 7-5 (column 49/row 3.25)). Taking into account the
recommendation to remain 10% below this, a speed of
1140 rpm should not be exceeded.
RPM
Outer diameter
72 mm 75.4 mm 122 mm
5305
5066
3131
3913
3736
2309
2653
2533
1565
2334
2229
1378
2122
2026
1252
2042
1950
1205
1724
1646
1018
1326
1266
783
1114
1064
657
1048
1001
618
862
823
509
1)
796
760
470
477
456
282
451
431
266
398
380
235
252
241
149
239
228
141
199
190
117
172
165
102
105
100
62
99
95
59
69
66
41
76
52
49
31
51
34
33
20
english
17