PTM-1100
Operators
Manual
7
PTM MODULE
STRAIN GAGE SENSOR INPUT
The strain gage sensor wires are connected at the green 5-pole
Weidmuller connector at the bottom of the module. Connections include
“+ Gage”, “+ Signal”, and “Shield”. For ease of wiring at the
connector, it can be removed from the module while making the 5 connections at the
screw terminals.
INITIAL SET-UP AND CALIBRATION
Zero Balance
After the proper wiring connections are made, the module should be set up by connecting a
good quality voltmeter to the 0-10 VDC analog voltage “Track” output terminals (“Track” and
“Acom”). There should be no load on the sensor, and the external timing input signal should
be off (between cycles). Set the small 3-position calibration toggle switch at the top of the
module to the center “Off” position. Adjust the “Gain” pot CCW until it reaches the stop, a
click will be felt. Adjust the small “Bal” (Balance) pot below the switch so that the voltmeter
reads 0.00 volts. This electronically “zero balances” the sensor to the module circuit.
Calibration: For Strain gage installations
The machine to which the sensors are mounted should be “field calibrated” using portable
calibration load cells and instrumentation to verify the actual developed tonnages.
1. With the small 3-position calibration toggle switch at the top of the module to the
center “Off” position, cycle the press and record developed tonnage.
2. Adjust the gain pot CW, and cycle the press again.
3. Compare the “Peak Output” scaled value on the display meter to the display of the
calibration equipment, and continue to adjust the gain pot and cycle the press.
Note: If the value remains 0 (zero), continue to increase the gain by rotating Clock-wise,
until the unit displays the developed value.
If there is not enough gain with the toggle switch at the tower LOW GAIN 140K position,
move it to the upper HIGH GAIN 1 Megohm position, then repeat the zero balance. The
corresponding voltage “Calibration Number” can be read from the track output with a
voltmeter, with the 3-postion calibration toggle switch in the “Cal” position.
The two available calibration resistor values available for the PTM-1 module are:
HIGH GAIN (1 MEGOHM CAL RESISTOR): UPPER SWITCH POSITION
This is for use typically with HT-400 Strain Gain sensors or other sensor
types where the deflection and signal output is low.
LOW GAIN (140K OHM CAL RESISTOR): LOWER SWITCH POSTION
This can be used with HT-400 Strain Gain sensors, in press load monitoring
applications where high deflection and signal output is present. It should
also be used with load cells having mid-range output (approx. 0.50-1.00
mV/V) or having high output (greater than 1.00 mV/V).
When the “Zero Balance” and “Calibration” procedures are completed, the toggle switch
should be set to the lower “A/Z” (Auto-Zero) position for normal operation.
