That looks like the original programmer was using the CPT to get a true volume.
Like Saffa said flow meters are set to a certain pulses/unit volume. In my business we call that a K-Factor. Meters with smart transmitters are normally adjustable but meters that just use a pickup coil or optical transmitter are fixed at at the factory to a NOMINAL K-Factor. In your case I would be willing to bet that your meters K-Factor is 100 Pulses/Unit Volume.
Now no meter is perfect so each meters actual K-Factor or the real pulses/unit volume is going to be more or less than the nominal. To check this, the meter is normally run into a vessel that has a known calibrated volume. The volume in the vessel divided by the meter volume is known in my business as the Meter Factor.
Since we don't normally change the K-Factor (this is for constancy) we use the meter factor to get a accurate reading. So to get a calibrated volume we would take the pulses/K-Factor * Meter Factor.
The CPT instruction you have is doing that with the * being first and / last, but either way it works.
So the .985 is the meter factor either made up or was actually checked against a known volume.