User's Manual

18
Reference Manual
00809-0300-4248, Rev AA
Section 2: Configuration
July 2014
Configuration
2.5.4 Fast Key sequence
Tab le 2 -2 lists the fast key sequences for common transmitter functions.
Note
The fast key sequences assume that DD Dev v1, DD v1 is being used.
2.5.5 Calibration
Calibrating the transmitter increases the measurement precision by allowing corrections to be
made to the factory-stored characterization curve by digitally altering the transmitter’s
interpretation of the sensor input.
To understand calibration, it is necessary to understand that smart transmitters operate
differently from analog transmitters. An important difference is that smart transmitters are fac-
tory-characterized, meaning that they are shipped with a standard sensor curve stored in the
transmitter firmware. In operation, the transmitter uses this information to produce a process
variable output, in engineering units, dependent on the sensor input.
Calibration of the 248 Wireless may include the following procedure:
 Sensor Input Trim: Digitally alter the transmitter’s interpretation of the input signal
Trim the transmitter
The Sensor Input Trim function may be used when calibrating.
Sensor calibration
Perform a sensor trim if the transmitters digital value for the primary variable does not match
the plant’s standard calibration equipment. The sensor trim function calibrates the sensor to
the transmitter in temperature units or raw units. Unless your site-standard input source is
NIST-traceable, the trim functions will not maintain the NIST-traceability of the system.
Table 2-2. Rosemount 248 Wireless fast key sequence
Function Key sequence Menu items
Device Information 1, 7 Identification, Revisions, Radio, Security
PV Range Values 2, 2, 3 PV LRV, PV URV, LSL, USL
Lower Range Value 2, 2, 3, 4
Set the temperature for the 0% point to configure the
Percent of Range
Upper Range Value 2, 2, 3, 3
Set the temperature for the 100% point to configure
the Percent of Range
Sensor Trim (Calibration) 2, 1, 6, 1 Lower Sensor Trim, and Upper Sensor Trim
Wireless Network 2, 2, 1 Network ID, Join to Network, Broadcast Info
Sensor Configuration 2, 1, 3
Configure Sensor Type and Units, View Current Sensor
Configuration
Fast Keys
3, 5, 2