Page 72
ST 800 Series HART/DE Option User’s Manual
Revision 5.0
7.3 Calibrating Range
The ST 800 SmartLine Pressure Transmitter supports two-point calibration. This means that when
two points in a range are calibrated, all points in that range adjust to the calibration.
The procedures in this section are used to calibrate a differential pressure (DP) Transmitter to a range
of 0 to 200 inH
2
O for example purposes. This procedure assumes that the Transmitter has been
removed from the process and is located in a controlled environment.
IMPORTANT! You must have a precision pressure source with an accuracy of 0.02% or
better to do a range calibration. Note that the factory calibrates ST 800 SmartLine Pressure
Transmitters using inches of water pressure reference to a temperature of 39.2
o
F (4
o
C).
Correcting the Lower Range Value (LRV)
1.
Connect a power supply and the MC Toolkit to the signal terminals of the Transmitter’s
terminal block.
2.
Connect the precision pressure source to the high pressure side of the DP-type Transmitter.
3.
Turn on the power supply, and allow the Transmitter to become stable.
4.
Turn the MC Toolkit on, start the FDC application.
5.
On the FDC Home page, select Online, and establish communication with the Transmitter.
6.
Select the My Device menu, and choose from the following selections:
a.
Device Setup \ Calibration \ Calibration Methods \ LRV Correct
7.
You will be prompted to remove the loop from automatic control. After removing the loop
from automatic control, press OK.
8.
When prompted, adjust the pressure source to apply pressure equal to the LRV (0%), and
press OK.
9.
When the pressure stabilizes, press OK.
10.
When prompted, remove pressure.
11.
On the next prompt – “Please enter current Calibration Time in 24 Hr Clock format (Hour
field)”, enter the hour portion of the calibration time in the 24 Hr format HH, for example
“12,” and press Enter.
12.
On the next prompt – “Please enter current Calibration Time (Minute field),” enter the
Minutes field MM (example 23), and press ENTER..
13.
When prompted to return the loop to automatic control, press ENTER
Correcting the Upper Range Value (URV)
1.
See Figure 14 for typical test connections. Connect the power supply and communicator to
the signal terminals of the Transmitter terminal block.
2.
Connect the precision pressure source to the high pressure side of the DP-type Transmitter.
3.
Turn on the power supply, and allow the Transmitter to become stable.
4.
Turn on the MC Toolkit, and start the FDC application into operation.
5.
On the FDC Home page, select Online, and establish communication with the Transmitter.
6.
Select the My Device menu, and choose one of the following options:
1.
Device Setup \ Calibration \ Calibration Methods \ URV Correct
7.
You will be prompted to remove the loop from automatic control. Press OK
8.
When prompted, adjust the pressure source to apply pressure equal to the URV (100%), and
press OK.
9.
When pressure stabilizes, press OK.
