Advanced Measurement Technology 273A, Руководство пользователя

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Model 273A Potentiostat/Galvanostat User’s Manual
Users might note that there is also a Cell switch at the electrometer. This switch has two
positions, DUMMY, and EXT. Its function is to determine whether the Model 273A is controlling
with respect to the external cell or with respect to an internal (dummy cell) resistor.
Note: This switch provides no protection in either position. The cable connections can be
handled safely only when the front panel cell disable switch is set to OFF.
Note that the Model 273A is controlled even when the cell isn't ON, that is, having the cell OFF
does not cause an overload condition.
It might be noted that, in the context of this discussion, Cell ON and Cell OFF refer to the path
from the Control Amplifier output to the Counter Electrode cable lead. The red indicator does not
respond to the status of the actual counter electrode connection. That connection could be
secure or faulty and it would have no effect on the red indicator, which responds only to the Cell
ON switch, the CELL ENABLE switch, and governing software. However, if the Cell is ON and
there is no connection to the counter electrode, the effect will be the same as if the cell had
infinite resistance and an E OVERLOAD will occur.
2.5. Defects and Abnormal Stresses
Whenever it is likely that the protection provided by the connection to earth ground has been
impaired, do not use the instrument and secure it so others cannot use it. The protection is likely
to be impaired if, for example, the apparatus:
1. Shows visible damage,
2. Fails to perform the intended measurement,
3. Has been subjected to prolonged storage under unfavorable conditions.
4. Has been subjected to severe transport stresses.
The instrument should not be used until its safety has been verified by qualified service
personnel.
2.6. Ventilation
The Model 273A incorporates forced-air ventilation to maintain a safe operating temperature.
Thus it is necessary to allow some free space (minimum 10 cm) behind the instrument so that
adequate air circulation can occur. Moreover, there must be adequate circulation between the
space behind the instrument and the general laboratory circulation to allow effective cooling. In a
typical installation, these requirements are satisfied with a large safety margin. If the Model 273A
is cabinet or rack mounted, some additional effort to assure adequate ventilation may be
required. Ambient Temperature: From 10°C to 40°C. The instrument shall operate from 10°C to
40°C but may not meet some temperature related specifications. The instrument shall operate
from 20°C to 30°C and meet all its specifications over this range. The ambient temperature
should not exceed 45° C (113° F).
2.7. This Apparatus as a Source of Radio Frequency Interference
In a typical application, it is unlikely that this apparatus will act as a source of noticeable radio
frequency interference. However, when operated near particularly sensitive equipment,
interference emanating from this apparatus could be a problem. Should this be the case, steps
can be taken to minimize that interference. A discussion of the recommended steps follows.