Should you need to calculate a fluid rate in drops per second, the easiest way to do this would be to use the medication calculator. 

What you would have to do is create a parameter in the medication section and follow the steps below:

1. Give your parameter a name, in medications section: PLA

2. Under concentration create 1 drop/drop (if not in the dropdown menu just type it in)

3. Then under the dosage section, indicate the rate you choose: 2 drops/sec. The Dose, will indicate the current rate you should set your patient to, in this case 1 drop/sec

This will then give you the calculated drops/sec dose for a patient with the correct weight, see example below for PLA.