Tech Note 107: Recalibrating CMCP505 Digital Displays <01/01/07
Last Updated: 05/10/2017
CMCP505 LED/LCD Displays sold prior to 01/01/07 can only be recalibrated to a different full scale by changing resistor R2. The existing R2 resistor may be removed using a soldering iron and solder sucker. R2 can then be carefully replaced after shaping and clipping the leads to the proper shape and length. If a solder sucker is not available simply clip out the resistor by cutting the leads close to the resistor body. The leads remaining in the board can then be stood up and new resistor soldered between them. Replacement resistors need to be 1% precision resistor, 1/4 watt.
After installing the proper resistor, apply 5.00 VDC to the input, the full scale value can be adjusted (tweaked) using the 3/4 turn potentiometer accessible through hole in circuit board. Do not force potentiometer over 3/4 turn or permanent damage will result.
If a 5.00 VDC supply is not readily available the voltage output of the CMCP500 Monitor can be used. Using the front selector switch select "Danger" for the danger alarm set point. Increase the set point to 5.00 VDC using a quality digital voltmeter. Adjust display as above then reset danger set point.
Decimal point location is changed by solder gaps SG1 (0.000), SG2 (00.00) and SG3 (000.0). Remove and add solder to the appropriate solder gap.
Engineering Unit Decimal Point Guideline:
in/sec = 0.00 (hundredths)
mm/sec = 00.0 (tenths)
mils = 00.0 (tenths)
microns = 000 (none)
temperature = 000 (none)