SenSmart 3000 User's Manual
Document: UM-1003
Revision Level B
16
at least 25ppm but not more than 100ppm. The indicated value should read within 15% of full
scale. Remember that this is only a coarse check and precision calibrations are performed in
Routine Sensor Calibrations
described in the following section 4.1. Section 6.4 describes
PREAMP GAIN adjustments that may be required if full-scale ranges are changed.
SECTION 4
– OPERATING INSTRUCTIONS
4.1
Routine Sensor Calibrations
Caution
: For calibration of R.C. Systems Inc. Millenium sensors refer to Section 8 for calibration
procedures. A Zero calibration of the sensor is the only calibration that is required. The
transmitter is factory calibrated and does not require routine calibration when using the Millenium
sensor.
Calibration is the most important function for insuring correct operation of the SenSmart 3000.
The CAL MODE (flow chart shown in Figure 4-2) is designed to make calibration quick, easy and
error free. A successful ZERO and SPAN calibration requires only four keystrokes. The 4-20mA
output indicates CAL MODE by transmitting 3mA for 2-wire installations and 1.5mA for 3-wire
installations. It then transmits 4mA during the subsequent CAL PURGE delay to prevent external
alarms during calibration. Local SenSmart 3000 alarm relays (if equipped) are inhibited during
CAL MODE. CAL MODE automatically exits if no keystrokes are detected after 5 minutes.
Follow these SenSmart 3000 calibration guidelines:
Calibration accuracy is only as good as the calibration gas accuracy. R. C. Systems
recommends calibration gases with NIST (National Institute of Standards and
Technology) traceable accuracy to increase the validity of the calibration.
Do not use a gas cylinder beyond its expiration date.
Calibrate a new sensor before use.
Allow the sensor to stabilize before starting calibration (approximately 5 minutes).
Calibrate on a regular schedule. (R. C. Systems recommends once every 3 months,
depending on use and sensor exposure to poisons and contaminants.)
Calibrate only in a clean atmosphere, which is free of background gas.