Model 2700 Transmitter
with Petroleum Software Option
Digital Signal Processing with MVD
Higher frequency drive
Analog, limited sampling
10 times less sensitive to signal noise
Enhanced patented algorithms
T
DSP, higher resolution
Digital circuitry
Faster Response Better Repeatability Less Parts More Reliable
Faster sampling
MVD Petroleum Software
The petroleum software version adds the following calculations to the standard 2700 software:
Calculates base density and Ctl (the correction for the effect of temperature on a liquid)
Calculates gross volume at standard temperature
Calculates flow weighted average temperature and average observed gravity (flowing density)
In order to meet the 0.5F accuracy in temperature measurement as required per API MPMS Chapter 7, an external RTD must be utilized.
The core processor must be mounted remote from the sensor in order to bring in the signal to the core processor from this external RTD.
Calculation of Base Density
The software utilizes API MPMS Chapter 11.1 to calculate the base density from the flowing density and the flowing temperature.
Base density can be calculated in degrees API at 60F, SGU at 60 F, or kg/cm3 at any reference temperature. The fluid being measured dictates the appropriate equation for the calculation of base density.
Base density and flowing density are both available as outputs from the 2700.
Calculation of Base Density
API Chapter 11.1 consists of computer procedures, however, tables were computed for reference.
Table A Generalized Crude Oil Table B Generalized Products Table C for Individual and Special Applications Table D for Lubricating Oils
API in Tables 5 and 6 Relative Density (SGU) in Tables 23 and 24 Kg/m3 in Tables 53 and 54
API Measurements
Calculation of Base Density
API MPMS Chapter 11.1 Tables 5A, 53A, and 23A covering generalized crude oil and JP4.
Table 5A, used for a base temperature of 60F, covers and API@60F range of 0 to 100 API. Table 53A, used for a base temperature of 15C covers a base density range of 610 to 1075 kg/m3. (Other base temperatures can be used.) Table 23A, used for a base temperature of 60F, covers a relative density@ 60F range of 0.6110 to 1.0760 SGU.
Limitations on API Chapter 11.1
The calculations are limited to the following:
Crude oil from 0 to 100 API (0.611 to 1.076 g/cc)
Generalized products from 0 to 84 API (0.657 to 1.076 g/cc) Temperatures from 0 to 300 F
The 2700 will show an alarm if the density or temperature goes outside the ranges of the table, however, it will continue to calculate.
Note: Core rev 2.2 or higher allows ranges outside the tables
Generalized Products
The tables identified for generalized products cover refined products such as
Gasolines Naptha Jet fuels, kerosene and Stoddard solvents
Diesel oil, fuel oil and heating oil
Fluids not covered by Chapter 11.1
Propane and propane mixes
Butane and butane Mixes Isopentane
Butadiene and butadiene mixes
LPG , LNG and NGL Ethylene and Propylene Cyclohexane and aeromatics Asphalts and road tars
Many of these fluids are metered on a mass basis thus eliminating the need for the calculation of base density.
MVD Petroleum Software
API and SGU are calculated as follows:
SGU = kg/m3 at 60 F / 999.012 (density of water at 60F) API = (141.5 / SGU) - 131.5
The industry utilizes API and SGU as units for both flowing density (sometimes referred to as observed gravity) and base density (sometimes referred to as corrected gravity).
Therefore, the software allows the use of API and SGU for flowing density. Flowing density in SGU = kg/m3 / 999.012.
API configuration screen using ProLink II
12
External RTD Configuration using ProLink II
Flow Weighted Averages
Computations for average temperature and average density (observed gravity)
Average values are based on one temperature and one density sample per unit of flow measurement. That is, each time a single unit of flow (barrel or whatever the user has selected) has been totaled, a sample of the current temperature and observed gravity is noted- the flow weighted average is the average of all the samples.
The weighted average for temperature and the weighted average for density are reset with the resetable totals. The reset function is available through the display with password security protection and through Prolink/HART.
Compressibility
The MVD Petroleum software does not utilize Chapter 11.2 to calculate Cpl (the effect of pressure on the density or the volume of the fluid.)
Therefore, the volume calculation is not net volume. The volume calculated is defined as gross volume at standard temperature.
Coriolis to a Flow Computer
Typically, the 2700 transmitter sends a pulse to the flow computer where net volume is calculated.
The pulse should represent gross volume.
Density (via analog or RS485) should represent flowing density.
All net volume calculations are then performed in the flow computer which has temperature and pressure inputs from individual line transmitters. Flow computers are required to meet API MPMS Chapter 21.2 for custody transfer.
The above application does not require petroleum software in the 2700.
Model 2500/2700 Output Assignments Configurable IO Output Board
mA HART Pv = Mass Flow Analog Output Frequency Output Volume Flow Mass Flow (not independently assignable) Density Mass Flow Volume Flow Temperature Volume Flow Density Drive Gain Discrete Output Temperature External Pressure FWD / REV Drive Gain External Temperature Event 1 API Corrected Density Discrete Input Event 2 API Corrected Volume Flow None Event 1 or 2 API Corrected Volume Total Start Zero Flow Switch API Corrected Volume Inventory Reset Mass Total Zero In Progress API Batch Avg Corrected Density Reset Volume Total Fault API Batch Avg Temperature Reset Corrected Volume Total API CTL (table used) Display Capabilities Sv = Same as Pv View Process Variables Tv = Mass flow View and Acknowledge Alarms Volume Flow Start, Stop, Reset Totalizers API Corrected Volume Flow Perform Output Simulation Tests Qv = Same as Pv plus Change Measurement Units Mass Total Scale Outputs Mass Inventory Cannot Change Channel Assignments Volume Total Volume Inventory
API Temperature Input Option #1
To meet API requirements, a user-supplied external temperature detector can be installed remotely by the user. This external temperature detector, instead of the RTD inside the sensor, is wired to a 9-wire 2700. The external RTD must be accurate to 0.1F (0.05C). RTD calibration information must be configured in the transmitter.
API Temperature Input Option #2
To meet API requirements, a user-supplied external HART temperature transmitter can be installed remotely by the user. This external transmitters process variable is read into the 2700 via HART. Using an external HART transmitter eliminates the primary analog of the 2700 from other use. The external RTD must be accurate to 0.1F (0.05C). HART polling for pressure compensation is now available as a second polled HART variable. This compensation is for the pressure effect on flow seen on some sensors, not pressure compensation for API Calculations.
