User manual

14
Section 1 MC-III™ EXP Flow Analyzer
Multipoint Linearization
The MC-III interface software supports up to 12 calibration points in addition to single-point calibration based
on the K-factor provided with the turbine owmeter. See K-Factor Type, page 66, for more information.
Gas Volume Correction
Gas turbine meters are calibrated in actual cubic feet (ACF), and measure gas in actual cubic feet. In some
applications, a user may benet from referencing gas measurements back to standard conditions by measuring
in terms of standard cubic feet (SCF). The MC-III EXP makes this process quick and easy, by using xed
average values for the owing gas temperature and owing gas pressure. See Gas Volume Correction, page 68,
for more information.
Input Options
The owmeter signal can be obtained from a magnetic pickup or a pre-amplier device. The sensitivity of the
owmeter input may be adjusted with the instrument keypad or the interface software. See Section 2, page 19,
for wiring diagrams. See Section 3, page 35, and Section 4, page 45, for conguration procedures.
Output Options
The MC-III EXP standard circuitry provides:
• a scaled pulse output representing an increment in volume for each pulse
• a loop-powered 4-20 mA output representing the ow rate
• a owmeter frequency output for use with remote equipment to derive ow rate and volume
• an RS-485 output for communication with interface software or other telemetry equipment
When the 4-20 mA rate output feature is used, the MC-III EXP is powered by the current loop, and the lithium
battery or alkaline battery pack is used as a backup supply.
The pulse output and 4-20 mA output features should be turned off when not required for reduced current
consumption. See Section 2, page 19, for wiring diagrams. See Section 3, page 35, and Section 4, page 45, for
conguration procedures.
Flow Log Archival
The MC-III EXP saves up to 384 daily logs and 768 hourly logs in nonvolatile memory. By connecting with
the interface software, users can download the logs for viewing and/or printing in tabular format or in a trend
chart.
Users can also export daily and hourly logs to a spreadsheet. For more information, see Section 5, page 79.
Event Log Archival
The MC-III EXP saves up to 345 user event logs. Event logs are generated to track user changes such as K-
Factor changes, input setting changes, power-on reset and “watch-dog” reset, ow cut-off and frequency cut-
off.
By connecting with the interface software, users can download the logs for viewing and/or printing in tabular
format. In addition to showing old and new values, each event log is time-stamped, and includes the register
associated with the change. For more information, see Section 5, page 79.
Password-Protected Security
A keypad security access code prevents unauthorized personnel from altering the calibration or accumulated
volume data in the instrument. The security feature may be disabled if this protection is not required.