Zero And Span Adjustment - Rosemount 1151DP Reference Manual

Reference Manual
00809-0100-4360, Rev BA
August 2008
Figure 4-9. Elevation and
Suppression Jumper Settings.
Zero and Span
Adjustment
Elevate Zero
E Output Option
(4-20 mA)
G Output Option
(10–50 mA)
NOTE: The jumper is located on the component side of the
amplifier board. Jumper positions may vary from those shown. The
board must be unplugged from the transmitter to gain access to
the component.
The zero and span adjustment screws are accessible externally behind the
nameplate on the terminal side of the electronics housing. See Figure 4-10.
The output of the transmitter increases with clockwise rotation of the
adjustment screws. The zero adjustment screw and ELEVATE
ZERO/SUPPRESS ZERO jumper do not affect the span. Span adjustment,
however, does affect zero. This effect is minimized with zero-based spans.
Therefore, when calibrations having elevated or suppressed zeros are made,
it is easier to make a zero-based calibration and achieve the required
elevation or suppression by adjusting the zero adjustment screw (and
ELEVATE ZERO/SUPPRESS ZERO jumper as required).
A degree of mechanical backlash is present in the zero and span
adjustments, so there will be a dead band when the direction of adjustment is
changed. Because of the backlash, the simplest procedure is to purposely
overshoot a larger amount before reversing the direction of the adjustment.
Rosemount 1151
Suppress Zero
Suppress Zero
Elevate Zero
4-15