Advanced Measurement Technology 273A, Руководство пользователя

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Chapter 5—Operating Instructions 53
Warning! Potentials as high as ±100 V could be present at the counter electrode lead's clip.
For safety, always have the front-panel cell enable switch in the off position when
handling the electrometer leads.
What this comes down to is that the user must make a decision in each application where
the electrometer is being used. If the decision is to ignore IR drops in the working electrode
lead (certainly reasonable at low current levels), simply connect the shorting plug between
the two jacks. If the decision is to eliminate this source of error, simply bring a lead from the
Sense jack directly to the working electrode. One connection or the other should be made;
never both.
In galvanostatic operation, one could conceivably choose not to monitor the potential with a
reference electrode and so not use the electrometer. Where this is the case, no harm would
come by operating with the Sense jack open. However, it is just as easy, and preferred, to
install the jumper. If the potential is monitored, the same remote (cell) versus local
(electrometer) sense considerations apply. The measured potential is affected by the iR
drop.
4. ELECTRODE LEADS: There are three leads, each terminated in a clip. The leads can be
readily identified by the color of the clip's insulating boot. Green identifies the Working
Electrode and red the Counter Electrode.
The polarity of the potential at the counter electrode will be opposite the "applied potential."
This is necessary to establish the correct polarity relationship at the working electrode versus
the reference electrode.
Black identifies the ground lead. It can be used to ground a piece of peripheral apparatus,
such as an electrostatic shield. Usually, this lead isn't used. TAKE CARE THAT THE
ELECTROMETER LEAD CLIPS NOT SHORT TOGETHER. Because the ground lead is
often unused, it tends to be overlooked, making the possibility of an accidental short
involving this lead more of a problem than for the other two.
5.5. Model 273A Standard Environmental Conditions
5.5.1. Operating Conditions
This equipment shall meet all specified performance criteria when subjected to any natural
combination of stress.
A. Input Voltages
1. 100/120 volts AC 50 to 60 Hz.
2. 200/240 volts AC at 50 to 60 Hz.
B. Ambient Temperature: From 10°C to 40°C
1. The instrument shall operate from 10°C to 40°C but may not meet some
temperature related specifications.
2. The instrument shall operate from 20°C to 30°C and meet all its specifications over
this range.