XITRON 2000I, Руководство пользователя, Страница: 56 / 96

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2000I & 2000M User Guide, Rev B
The 2000 instruments can be operated in parallel with a sending unit of a
transducer having the above characteristics. Use the instrument to modify the
transducer indication by entering the data entry as given above, except with
the 4mA offsets removed. Thus output
A
and output
B
will be 0mA and 16mA
respectively, and user
A
and user
B
will be 0psi and 100psi respectively. The
instruments output the required correction, in the units used by the
transducer. Note that this correction may be of either polarity.
Note:
The entered data are non-volatile, thus they may be entered at your
base location, and then be used at a remote site without the need to reenter
these data. Refer to
Using the Memory Options .
Adjusting Current Measuring of Multiple Units
The 2000 instruments may be used to adjust multiple-current measuring
equipment simultaneously. This is achieved by connecting the units in series.
Here the 18V compliance capacity of the 2000 instrument allows for as many
as 15 units to be adjusted simultaneously. When connecting line-powered
current measuring equipment in series check for excessive leakage-current
flowing from an input terminal to ground. Current leakage does not affect the
measurement when a single unit is connected, but each unit will affect the
indications of others when connected in series.
Also many highly-sensitive current measuring devices have inferior rejection
to interference on one of their input terminals. When connected in series the
interference generated by one unit can adversely affect the performance of the
next. To operate multiple units in series, test for loss of accuracy during this
procedure. Before adjusting any equipment check the calibration of each unit
individually, then connect the equipment in series and recheck.
Note: The low output impedance of the 220mV and 22mV ranges of the
2000 instruments enable a small correction factor to be easily applied when
the instrument is driving low load impedances.
Simulating Thermocouple Systems
2000M instrument can be used to simulate single and dual junction
thermocouple systems. This instrument offers the choice of using the internal
cold junction
compensation or using an external high accuracy ice-point
reference junction. When using internal cold junction compensation to