5.8 Lower display: ‘di5P-2’
When only one display is required this function
allows the lower display to be disabled. To reveal
if the lower display is activated select 'di5P-2' from
the configuration menu and press
P
. If set as
required, press
E
to return to the configuration
menu, or press the
▲
or
▼
button to toggle the
function between ‘on’ and ‘oFF’. When set as
required press
E
to enter the selection and to
return to the configuration menu.
5.9 Position of the decimal points: ‘dP’
This function defines the position of the decimal
point in both the rate and total displays.
Rate display
The rate display can have up to five digits plus
sign, the decimal point may be positioned
between any of the digits, or may be omitted.
The BA558E uses
floating point arithmetic
so
moving the position of the rate display decimal
point will affect totalisation.
Total display
The total display can have up to eight digits or
seven digits with a negative sign, the decimal
point may be positioned with up to five digits
after it, or it may be omitted.
Notes:
a. The position of the decimal point in the
Grand Total will be the same as that
selected for the Total Display.
b. If the total display decimal point can’t be
moved to the left it is likely that the existing
display will be over-ranged by the
adjustment. The total display should be
reset to zero, which should allow the decimal
point to be positioned as required.
c. If the decimal point is moved to the right, the
existing total display will be truncated, not
rounded, the lost precision can not be
recovered.
Positioning the decimal points
To adjust the position of either the rate or total
display decimal point select 'dP' from the
configuration menu and press
P
. The upper
display defined as the rate or total display by
function ‘di5P-1’ (section 5.7) will be activated
and identified. The decimal point can be
positioned by operating the
▼
or
▲
push
button, when set as required enter the setting
and return to the conditioning menu by
operating the
E
button. Alternatively, to position
the lower display decimal point press the
P
button which will display and identify the lower
display variable, but on the larger upper display.
The position of the decimal point can be
positioned in the same way by operating the
▼
and
▲
push buttons, when set as required
enter the setting and return to the conditioning
menu by operating the
E
button.
5.10 Calibration of the rate display using an
external current source: ‘CAL’
This function enables the zero and span of the rate
display to be adjusted using an external calibrated
current source. When used with an accurate
traceable current source this is the preferred
method of calibration.
Zero
rate display with 4mA input
Span
rate display with 20mA input
To calibrate the rate display select 'CAL' from the
configuration menu and press
P
.
The BA558E will
display 'ZEro' which is a request for a 4mA input
current. Adjust the external current calibrator to
4.000mA and again press
P
which will reveal the
current zero rate display. The flashing digit of the
display can be changed by pressing the
▲
or
▼
buttons, when set as required pressing
P
will
transfer control to the next digit. When all the
digits have been adjusted, press
E
to enter the
new zero and return to the 'ZEro' prompt .
Pressing the
▲
button will cause the BA558E to
display '5PAn' which is a request for a 20mA input
current. Adjust the external current calibrator to
20.000mA and again press
P
which will reveal the
existing span rate display. The flashing digit of the
display can be changed by pressing the
▲
or
▼
buttons, when set as required pressing
P
will
transfer control to the next digit. When all the
digits have been adjusted press
E
t
o enter the new
rate span and return to the '5PAn' prompt. Finally
press
E
again to return to the configuration menu.
Notes:
a. The Rate Totaliser input current must be
adjusted to the required value before the zero
and span functions are entered by pressing the
P
button.
b. Rate Totalisers may be calibrated at currents
other than 4 and 20mA, within the range 3.8 to
21.0mA providing the difference between the
two currents is greater than 4mA. If these
conditions are not complied with, the
instrument displays ‘FaiL’ and aborts the
calibration.
c. If the zero current is greater than the span
current the instrument will be reverse acting
i.e. an increasing input current will cause the
display to decrease.
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