🔍 Key Concepts

• Study how the liquid sensor is powered and what kind of signal it sends to the MARST1 alarm unit. • Look at the MARST1 Alarm Indications Program Unit table and note which codes (A06, A07, etc.) are associated with the liquid sensor and its signal quality. • Think about what happens to a pneumatic or air‑operated transducer when its supply air is shut off: does it look like normal liquid detection or a sensor malfunction?

💭 Think About

• Follow the supply air line to the liquid sensor in the drawing. If that air is secured, will the sensor still be able to transmit a valid measurement to the MARST1 unit? • Compare the alarm descriptions for AO6 and AO7. Which one describes an actual liquid condition in the separator, and which one describes a problem with the sensor or its signal? • Ask yourself: would shutting off the air make the system think there is liquid present, or would it make the system think the sensor is not working correctly?

✅ Before You Answer

• Verify which MARST1 alarm code in the table is tied specifically to liquid indication and which to a transducer fault. • Confirm from the schematic that the liquid sensor depends on supply air to function; imagine what the output becomes with no air pressure. • Before choosing, be sure your option matches a sensor failure condition, not a genuine process condition in the oil inlet or outlet lines.