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Example below shows the speed information for 150 RPM:
This example has an INPUT FREQUENCY RANGE of 0 .166 Hz to 2 .50 Hz . By installing 1
(one) target on the roller or shaft, the following formula can be used to convert to RPM’s:
INPUT FREQUENCY * 60 = RPM
Examples:
0 .166 Hz * 60 = 9 .96 RPM
1 .33 Hz * 60 = 79 .80 RPM
2 .50 Hz * 60 = 150 .00 RPM
This example unit has a factory set span of 2 .334 Hz (2 .50 Hz - 0 .166 Hz) . Multiplying 2 .334
Hz * 60 will give the span in RPM’s .
2 .334 Hz * 60 = 140 .04 RPM
Dividing 140 .04 / 160 will give the RPM resolution for each .1mA increment .
140 .04 / 160 = 0 .87 RPM per .1mA output
By adding additional targets to the roller or shaft, a lower RPM range can be obtained . The
following examples will show how to calculate the speed range for 4 (four) targets .
INPUT FREQUENCY * 60 / 4 TARGETS = ACTUAL RPM
Examples:
0 .166 Hz * 60 / 4 = 2 .49 RPM
1 .33 Hz * 60 / 4 = 19 .95 RPM
2 .50 Hz * 60 / 4 = 37 .50 RPM
CONCLUSION: By changing the number of targets on the roller or shaft, different speed
ranges can
be obtained from the same model .
Examples:
1 Target = 9 .96 RPM to 150 .00 RPM
2 Targets = 4 .98 RPM to 75 .00 RPM
4 Targets = 1 .77 RPM to 37 .50 RPM
Specification - 37545 Smart Monitor 120VAC 4029mA output
• AC Input: 90-140 VAC 50/60 Hz @ 6 W
• Fuse Protected: 1 amp
• Output: Proportional 4-20mA D . C .
• Linearity: Better than 1%
• Accuracy: Better than 1%
• Repeatability: Better than 5%
FIGURE A5 .3: 37543 Smart Monitor dimensions .
