You can’t always plan for every loop condition in a chemical plant. Sometimes input cards are active and sometimes passive. Field transmitters are sometimes line powered (four-wire) which usually have active outputs, and sometimes they are passive (two-wire). Has the Basic Process Control System been updated with HART smart input cards? Has there been a new asset manager installed that needs the HART signal?
When those unplanned situations exist, you can turn to the HIT HART Pass-through Signal Isolator. The HIT isolator provides superior noise rejection and full three-way isolation with HART pass-through capability. Another very important feature of the HIT is that the output will track the input all the way to 0mA when it fails; as opposed to most other isolators that simply go to 4mA – which is always difficult to ascertain between a failure of the input or just 0% scale. Lastly, the HIT can be used on non-HART or HART based loops when asset managers need that valuable diagnostic and calibration data.
- Class I Div 2/Zone 2 approval
- HART pass-through capability
- Output tracks to 0mA on failed input