Table 5-1: API tables, process fluids, measurement units, and default reference values
(continued)
Process fluid
API tables
(calculations)
Referred density
(API): unit and
range
Default
reference
temp
Default
reference
pressure
API standard
Referred
density
CTL or
CTPL
59E
60E
Unit: kg/m
³
20 °C
0 psi (g)
(1)
Each API table represents a specialized equation defined by the American Petroleum Institute for a specific combination
of process fluid, line conditions, and output.
(2)
Referred density is calculated from line density. You must specify this table, either directly or by selecting the process
fluid and base density measurement unit.
(3)
You do not need to specify this table. It is invoked automatically as a result of the previous table selection.
(4)
CTL or CTPL is calculated from the result of the referred density calculation. A, B, C, and D tables calculate CTPL, which
is a correction factor based on both line pressure and line temperature. E tables calculate CTL, which is a correction
factor based on line temperature and pressure at saturation conditions (bubble point or saturation vapor pressure).
(5)
The Thermal Expansion Coefficient (TEC) replaces the referred density calculation. Use the CTL/CTPL table instead.
5.1.5 Process variables from the API referral application
The API referral application calculates several different process variables according to API standards.
CTPL
Correction factor based on line temperature and line pressure. CTPL is applied when
the API referral application is configured for an A, B, C, or D table.
CTL
Correction factor based on line temperature and pressure at saturation conditions.
CTL is applied when the API referral application is configured for an E table.
Referred density
The measured density after CTL or CTPL has been applied.
API volume flow
The measured volume flow rate after CTL or CTPL has been applied. Also called
temperature-corrected volume flow
.
Batch-weighted
average density
One density value is recorded for each unit of flow (e.g., barrel, liter). The average is
calculated from these values. The average is reset when the API totalizer is reset. Not
available unless a totalizer has been configured with
Source
set to Temperature-
Corrected Volume Flow.
Batch-weighted
average
temperature
One temperature value is recorded for each unit of flow (e.g., barrel, liter). The
average is calculated from these values. The average is reset when the API totalizer is
reset. Not available unless a totalizer has been configured with
Source
set to
Temperature-Corrected Volume Flow.
API volume total
The total API volume measured by the transmitter since the last API totalizer reset.
Also called
temperature-corrected volume total
. Not available unless a totalizer has
been configured with
Source
set to Temperature-Corrected Volume Flow.
API volume
inventory
The total API volume measured by the transmitter since the last API inventory reset.
Also called
temperature-corrected volume inventory
. Not available unless an inventory
has been configured with
Source
set to Temperature-Corrected Volume Flow.
Configure process measurement applications
Configuration and Use Manual
March 2019
MMI-20025166
70
Micro Motion Model 5700 Transmitters with Configurable Outputs
