Honeywell VRX180 user manual Routine Maintenance, Calibrate Analog Inputs

Maintenance

8.2 Routine Maintenance

CAUTION

Calibrate the instrument routinely to ensure conformity to specifications. Calibration is to be performed by qualified service personnel only.

Clean the front panel with a damp cloth. If needed, use a detergent containing no abrasives. Always clean the front panel with the bezel closed. Do not use solvent cleaners.

Failure to comply with these instructions may result in product damage.

8.3 Set Mode

Select this to change the operating mode to Online or Program.

NOTICE

Changing to ONLINE mode by pressing any of the Display buttons can cause incorrect values to be displayed. The values will correct themselves in a few seconds. To avoid this potential annoyance, change to online mode through SET MODE instead of through the Display buttons.

8.4 Calibrate Analog Inputs

Note: the unit must be allowed to warm up for 30 minutes at the intended operating temperature prior to calibration.

Selecting the CALIBRATE ANALOG INPUTS lists a number of calibration functions you can perform.

Selecting the CALIBRATE ANALOG INPUTS again allows you to specify the AI module and channel in which to calibrate. When you Select Input, you must apply a 0% reference (low point calibration) value to the terminal block of the module channel. Then select CALIBRATE to start the calibration routine. After calibration of 0% value is completed, apply a 100% range value to the channel input terminals and then begin the calibration routine for 100% input (high point calibration).

When 100% range value calibration is completed, the controller compares the new 0% and 100% range values against the current 0% and 100% values. If the span of the 0% and 100% readings is less than 20% of the sensor range, the new values are rejected and the current calibration is retained.

Each channel must be calibrated for the specific input type to be applied to that channel. Calibration values can be copied from one channel to all other channels of like input type and range.

NOTE: Signal generators should have an accuracy of at least 0.05 %. The type of wires depends on the sensor used. Wait for 5 minutes after that particular sensor is connected (for compensation wires only).

WARNING

In thermocouple pay attention to the ambient temperature. If you are using a mV generator instead of direct thermocouple generator, the leadwires are in copper and you have to subtract from the mV value the mV corresponding to the ambient temperature of the rear terminals. (This eliminates the effect of the cold junction compensation).

Failure to comply with these instructions could result in death or serious injury.

Video Recorder – User Manual 245