 Basics of Flow Meter Totalizer

Basics of Flow Meter Totalizer and examples on flow total flow count.

Let’s say that our fullscale is 600 gallons per minute. When we’re speaking about fullscale, this means the maximum flow we expect, not the current flow. Say we want to pulse the relay for every 20 gallons that have passed by the sensor. There is a setting in the totalizer screen called the “ Units Per Pulse ” ( UPP ).

Flow Meter Totalizer

Example 1:

Fullscale is 5 MMSCFD

We want the totalizer to pulse every 1000 SCF

Let’s calculate the minimum UPP we can use, just to make sure we don’t violate the 1Hz rule. Since our fullscale is 5 MMSCF D (per day), we divide it out until we get seconds. UPP = 5 / 86400 (60 sec * 60 min * 24 hours = 86400 seconds) = 0.00005787 MMSCF S (per second). We now know that whatever value we use for the UPP, it must be equal or greater than this value to honor the 1Hz rule.

Now we want to pulse the totalizer every 1000 SCF. Since we are in MM units for the fullscale, we must convert the 1000 to MM to make both numbers equal regarding units. 1000 SCF = 0.001 MMSCF. So, setting the UPP=0.001 tells the meter to pulse the totalizer every 0.001 MMSCF units, or every 1000 SCF. Since the 0.001 value is greater than the minimum UPP of 0.00005787, we have not violated the 1Hz rule.

Fullscale is 5 MMSCFD

We want the Totalizer to pulse every 1000 SCF

Set the UPP=0.001

It should be noted that the UPP value must be in the same units as the fullscale. Since we are in MM units, the value in the UPP must also be in MM units; hence why the 1000 = 0.001 (MM).

Example 2

Fullscale is 22,000 gal/h

We want the Totalizer to pulse every 5 gal

Let’s calculate the minimum UPP. 22,000 gal/h = 22,000/3600 (60 sec * 60 min) = 6.1111. So our minimum UPP cannot be lower than 6.1111 gal for the 1Hz rule.

We want to pulse the totalizer relay every 5 gal. Setting the UPP = 5 would not work as the minimum UPP is 6.1111! Tricked you! This is a bad example.

So as you can see, we cannot do a relay pulse every 5 gallons as it violates the 1Hz rule.

Example 3:

Fullscale is 22,000 gal/h

We want the totalizer to pulse every 15 gal

Since the 22,000 and the 15 are in the same units (meaning they’re not MM nor M), we can leave the numbers alone. We set the UPP=15 to indicate we want a pulse every 15 gallons that have flowed by.