Sensor Electronics SEC 3000 Instruction And Operation Manual page 7

Warm-up
When power is applied to the detector, it enters a one (1) minute warm-up mode. The output current will be
0.8 mA during the warm up time period. At the end of the warm-up period with no faults present, the
detector automatically enters the normal operating mode (4 mA). If a fault is present after warm-up, the
detector current output will indicate a fault.
electrochemical sensors will take up to 24 hours to stabilize. Newly installed sensors should be calibrated
after they have been allowed to stabilize.
Normal
In the normal operating mode, the 4 to 20 mA signal levels correspond to the detected gas concentration.
The detector continuously checks for system faults or initiation of calibration and automatically changes to
the appropriate mode.
The 4 to 20 mA output of the SEC 3000 is a non-isolated current source.
Once the fault is cleared the SEC 3000 will automatically resume normal operation.
See the following chart for fault code status.
Current Output and Corresponding Status
Current Output
0-20 mA Normal measuring mode
0.0 mA Unit Fault
0.8 mA Unit warm up
1.2 mA Zero drift fault
1.6 mA Calibration fault
2.0 mA Unit spanning
2.2 mA Unit zeroing
4-20 mA Normal measuring mode
4.0 mA Zero gas level
5.6 mA 10% Full Scale
8.0 mA 25% Full Scale
12 mA 50% Full Scale
16 mA 75% Full Scale
20 mA Full scale
>20 mA Over-range
6
Status.
Some