Emerson Process Management 1500 manual Example, 6.10Configuring slug flow limits and duration

Optional Transmitter Configuration

4.Specifying the setpoint – the value at which the event will occur or switch state (ON to OFF, or vice versa).

Note: Events do not occur if the process variable equals the setpoint. The process variable must be greater than (Active High) or less than (Active Low) the setpoint for the event to occur.

Example	Define Event 1 to indicate that the mass flow rate in forward or
	backward direction is less than 2 lb/min.
	1.	Specify lb/min as the mass flow unit.
	2.	Set Flow Direction to Absolute Value.
	3.	Select Event 1.
	4.	Configure:
		• Variable = Mass Flow Rate

• Type = Active Low

• Setpoint = 2

ProLink II automatically displays event information on the Informational panel of the Status window and in the Output Levels window.

6.10Configuring slug flow limits and duration

Slugs – gas in a liquid process or liquid in a gas process – occasionally appear in some applications. The presence of slugs can significantly affect the process density reading. The slug flow parameters can help the transmitter suppress extreme changes in process variables, and can also be used to identify process conditions that require correction.

Slug flow parameters are as follows:

•Low slug flow limit – the point below which a condition of slug flow will exist. Typically, this is the lowest density point in your process’s normal density range. Default value is 0.0 g/cm3; range is 0.0–10.0 g/cm3.

•High slug flow limit – the point above which a condition of slug flow will exist. Typically, this is the highest density point in your process’s normal density range. Default value is 5.0 g/cm3; range is 0.0–10.0 g/cm3.

•Slug flow duration – the number of seconds the transmitter waits for a slug flow condition

(outside the slug flow limits) to return to normal (inside the slug flow limits). If the transmitter detects slug flow, it will post a slug flow alarm and hold its last “pre-slug flow” flow rate until the end of the slug flow duration. If slugs are still present after the slug flow duration has expired, the transmitter will report a flow rate of zero. Default value for slug flow duration is 0.0 seconds; range is 0.0–60.0 seconds.

46 Micro Motion® Model 1500 Transmitters with the Filling and Dosing Application