Advanced Measurement Technology 273A, Руководство пользователя

Страница: 38 / 70

32
Model 273A Potentiostat/Galvanostat User’s Manual
FUNCTION 18, FIRST EXTRAPOLATION POINT: This function sets the first of the two times
used to do the correction extrapolation in Current Interrupt IR Compensation. The range is 2 to
1997. The default value is 10 µs on the 1 A range and on the 100 mA range. It is 75 µs on all
other ranges. Note: The sum of the values of Functions 18 and 19 must be
1999 µs.
FUNCTION 19, SECOND EXTRAPOLATION POINT: This function sets the increment from the
first time to do the correction extrapolation in Current Interrupt IR Compensation. The range is 2
to 1997. The default value is 10 µs on the 1 A range and on the 100 mA range. It is 75 µs on all
other ranges. Note: The sum of the values of Functions 18 and 19 must be
1999 µs.
FUNCTION 20, IOFFSET VALUE PRESENT: This function reads the IOFFSET value present
(unlike the SET I OFFSET button on the front panel, which resets IOFFSET to the present
reading).
FUNCTION 21, CALIBRATE 273A: This function is used to calibrate the Model 273A.
6. [OVERRIDE]: This key allows the user to make specific modifications to the setup routines.
An override is accessed by keying [OVERRIDE] followed by the number corresponding to
the Override wanted. At that point the override's name and status are displayed. The [1 YES]
and [2 NO] keys are then used to specify the status of the selected override. The state can
be reversed with the YES or NO key, as appropriate. [1 YES] and [2 NO] are dual function
keys. YES and NO apply to the overrides; "1" and "2" belong to the numeric keypad.)
A number of overrides have been provided to extend the Model 273A's flexibility, power, and
ease of operation. Although memory space for 90 Overrides has been provided (range is 10 to
99), the number actually available is much smaller. The first available Override is OVERRIDE
10, the next is OVERRIDE 11, and so forth, up to the highest one defined. Once one of the
overrides has been called up, the Scan Setup UP/DOWN ARROW KEYS can be used to reach
the others via scrolling. A brief description of each follows.
OVERRIDE 10, OFFSET DISPLAY I: This Override determines whether I Offset, as set by the
SET I OFFSET key in the OUTPUT control group, will influence the displayed current. If YES, I
OFFSET will affect both the level at the OUTPUT connector and the displayed current. If NO
(default status), only the level at the OUTPUT connector will be affected.
OVERRIDE 11, UPDATE COULOMBS: This override determines whether the coulombs
indication will be periodically updated as the experiment progresses. If YES (default status), the
displayed coulomb accumulation will be updated every timebase. If NO, coulombs are not
measured. NO is normally selected if speed of data acquisition is the main concern, such as
might be the case in remote control experiments.
If the Model 273A is being controlled from an external computer via the RS-232C or GPIB inter-
face, the rate at which data can be taken will be faster with this override in the NO state.
OVERRIDE 12, CORRECT DISPLAYED E: This override determines whether the displayed
potential will be affected by the IR compensation. If YES (default state), the displayed potential
will be corrected for IR drop (assuming that IR Compensation is in use), the same as the
potential at the E MONITOR and recorder outputs. If NO, any errors due to IR drop will affect the
displayed potential as well, even though IR Compensation is in use. Note: IR drop errors always
affect the rear-panel ELECTROMETER MONITOR output, whether or not IR Compensation is
active.
OVERRIDE 13, CELL OFF AT END: This override determines the Cell ON/OFF status at the
end of a scan. If YES, the cell will be turned off (counter electrode connection interrupted) at the
end of the scan. If NO, the counter electrode connection remains intact and the final E/I
continues to be applied. Note that in the CONTINUOUS control mode, the experiment doesn't
end until the STOP key is pressed. At the point, the cell status is that determined by this
override.