Thread Size
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
3/4-20
M16 x 1.5
M16 x 1.5
M16 x 1.5
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
5/8-18
Part
Number
70085-1010-405
70085-1010-413
70085-1010-005
70085-1010-541
70085-1010-542
70085-1010-327
70085-1010-540
70085-1010-328
70085-1010-543
70085-1010-414
70085-3030-222
70085-1010-425
70085-3030-235
70085-3030-237
70084-1713-111
70085-1010-001
70085-1010-003
70085-1010-018
70085-1010-118
70085-1010-002
70085-1010-175
70085-1010-026
70085-1010-408
70085-1010-028
70085-1010-004
70085-1010-469
70085-1010-131
70085-1010-214
70085-1010-078
70085-1010-137
70085-1010-220
70085-1010-421
70085-1010-424
70085-1010-081
70085-1010-544
70085-1010-411
70085-1010-329
70085-1010-330
70085-1010-412
70085-1010-404
70085-1010-406
70085-1010-417
70085-1010-420
70085-1010-403
70085-1010-415
70085-1010-416
70085-3030-111
70085-3030-112
70085-3030-113
70085-3030-114
70085-3030-211
70085-3030-212
70085-3030-213
70085-3030-214
70085-8080-003
Output *
Guarentee
Voltage
(P-P)
9.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
4.9
13.4
13.4
13.4
3.4
3.4
3.4
3.4
12.9
12.9
12.9
12.9
21.5
4.3
4.3
15.1
15.1
3.4
3.4
12.8
4.9
4.9
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
13.4
9.4
9.4
9.4
13.4
13.4
13.4
13.4
9.4
13.4
9.4
9.4
12.8
Termination
Thread
Length
(in)
Sensor
Length
(in)
Cable
Wires
Wires
Cable
Cable
Wires
Cable
Wires
Cable
Wires
Cable
Connector
Cable
Cable
Connector
Connector
Connector
Connector
Connector
Connector
Connector
Connector
Connector
Connector
Wires
Wires
Cable
Cable
Wires
Wires
Wires
Connector
Connector
Wires
Cable
Wires
Wires
Wires
Wires
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Cable
Wires
2.75
1.5
1.875
1.88
2.75
2.75
4
4
6
6
2.75
3
1.5
1.5
1.125
1.125
2.625
3.625
5
1.125
2.625
3.625
5
1.437
1.125
2.750
1.687
2.937
1.812
2.937
2.937
2.475
4.493
1.5
1.88
1.875
2.75
4
6
1.5
2.75
4
6
1.5
4
6
1.5
2.75
4
6
1.5
2.75
4
6
1.812
4
2.75
3.125
3.13
4
4
5.25
5.25
7.25
7.25
4
4.125
2.75
2.75
2.5
2.25
3.75
4.75
6.125
2.25
3.75
4.75
6.125
2.53
2.125
3.75
1.687
2.937
1.812
2.937
2.937
3.6
5.618
2.75
3.13
3.125
4
5.25
7.25
2.75
4
5.25
7.25
2.75
5.25
7.25
2.75
4
5.25
7.25
2.75
4
5.25
7.25
1.812
* Output is based on .030" air gap at 500 IPS
4
Agency Temp Rating
Approval
(deg C)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-55 to 220
-65 to 95
-65 to 95
-20 to 220
-20 to 220
-65 to 95
-20 to 220
-65 to 95
-20 to 220
-65 to 95
-65 to 95
-55 to 107
-65 to 95
-65 to 95
-40 to 150
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-70 to 107
-70 to 107
-70 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-65 to 95
-20 to 220
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-20 to 220
-20 to 220
-20 to 220
-20 to 220
-55 to 220
-55 to 220
-55 to 220
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-65 to 95
-55 to 107
Page
19
18
18
19
19
18
19
18
19
18
20
12
20
20
11
8
8
8
8
8
8
8
8
9
9
9
10
10
10
10
11
12
12
18
19
18
18
18
18
19
19
19
19
19
19
19
20
20
20
20
20
20
20
20
11
AI-Tek Instruments, Cheshire, CT USA
Passive Sensor Selection Guide
Passive Sensor Selection Guide
Thread Size
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
.375 no thd
.375 no thd
1/4-40
1/4-40
1/4-40
10-32
10-32
10-32
10.32
Part
Number
70085-1010-007
70085-1010-056
70085-1010-086
70085-1010-355
70085-1010-041
70085-1010-428
70085-1010-458
70085-1010-174
70085-8080-001
70085-1010-314
70085-8080-004
70085-1010-024
70085-1010-472
70085-1010-227
70085-1010-037
70085-1010-299
70085-1010-182
70085-1010-289
Output *
Guarentee
Voltage
(P-P)
1.6
1.6
3.6
3.6
2
2
2
3.6
4.2
4.2
4.2
0.4
0.4
0.4
0.6
0.6
0.3
0.3
Termination
Thread
Length
(in)
Sensor
Length
(in)
Wires
Wires
Wires
Wires
Wires
Wires
Wires
Wires
Wires
Cable
Cable
Wires
Wires
Wires
Wires
Wires
Wires
Wires
0.812
3.625
0.812
0.812
0.812
1.5
3.625
0.812
1.5
1.375
2.5
0.687
0.687
1.687
0.5
1.25
0.5
1.25
1.252
4.065
1.252
1.252
1.252
1.94
4.065
1.252
1.5
1.375
2.5
1
1.187
2
0.5
1.25
0.5
1.25
Agency Temp Rating
Approval
(deg C)
-55 to 107
-55 to 107
-55 to 107
-55 to 107
-73 to 232
-73 to 232
-73 to 232
-65 to220
-55 to 107
-30 to 85
-30 to 85
-73 to 232
-73 to 232
-73 to 232
-55 to 107
-55 to 107
-73 to 232
-73 to 232
Page
13
13
13
13
14
14
14
14
15
15
15
16
16
16
17
17
17
17
AI-Tek Instruments, Cheshire, CT USA
* Output is based on .030" air gap at 500 IPS
5
Magnetic Sensor Selection
The following information is supplied for assistance in selecting the proper sensors for your
particular applications. One of the fundamental questions to be answered is, “Will there be enough
sensor output voltage at the lowest operating speed?”
The sensor output voltage depends on:
• Surface Speed - speed target passes pole piece
• Gap - distance between target and pole piece
• Target Size - geometric relationship of pole piece and target
• Load Impedance - connected to sensor
The surface speed of a gear depends upon its diameter and RPM. Surface speed is expressed in
terms of inches per second (IPS).
Surface Speed (IPS) = RPM x Outside Dia. (in.) x π
60
There is an optimum pitch (or tooth size) to
obtain the highest possible output from a sensor,
but this is seldom necessary. Figure 4 illustrates
the relationship of tooth size and spacing for
optimum magnetic sensor output. Using a fine
tooth gear, relative to a large pole piece diameter
sensor, results in a lower generated voltage
because the flux also passes into adjacent teeth,
resulting in a lower total flux variation.
Table A: Relative Output Vs. Gear Pitch
Pole Piece
Dia. (in)
8
12
.187
.106
.093
.062
.040
1.00
1.41
1.25
0.95
1.00
0.83
1.41
1.25
1.07
1.00
Gear Pitch
16
20
24
0.33
1.27
1.25
1.00
1.00
0.16
1.00
1.00
1.00
1.00
—
0.70
0.75
0.92
1.00
32
48
—
0.28
0.37
0.90
0.90
—
0.07
0.12
0.36
0.60
1. Dimension of tooth
top surface
4 Pole piece diameter
2. Tooth height
5. Air gap
3. Space between teeth
6. Gear face width
For maximum control and approximately sinusoidal
waveform, the following conditions should be obtained:
(1) equal to or slightly less than (4)
(2) equal to or more than (3)
(3) approximately 1.5 to 3 times (4)
(5) as small as possible, .005” minimum
(6) equal to or more than (4)
Figure 4: Sensor output as a function
of gear tooth size.
The load impedance, with relation to the internal impedance of the sensor, dictates the amount
of sensor output voltage that will be seen by that load. Magnetic sensors are designed with the
lowest practical impedance consistent with providing maximum output. The load impedance should
be high in relation to the impedance of the sensor to minimize the voltage drop across the coil and
to deliver the maximum output to the load.
Most of the output voltages listed in this catalog are based on a load impedance of 100k ohms.
To use a generality, the load impedance should be 10 times that of the sensor.
6
In order to assist you in selecting your sensor, Al-Tek Instruments has developed an output vs.
speed curve for each sensor family. By looking at the application extremes of highest speed/lowest
gap and lowest speed/highest gap, the full variation of sensor output can easily be determined. We
also specify each family in two ways: Standard - minimum output voltage at 1000 IPS, 0.005 in.
gap. Guarantee Point - minimum output voltage at 500 IPS, 0.030 in. gap. Sensors with .187” dia.
pole piece are tested with an 8 D.P. gear, 100k ohms load; .106” dia. & smaller pole piece sensors
are tested with a 20 D.P. gear, 100k ohms load. Sensors with connectors also use a 250 pf capacitor shunted across the load.
AI-Tek Instruments, Cheshire, CT USA
The relationship between pole piece diameter and
gear pitch and its effect on the output of a sensor
is described in Table A.