BEKA BA578C, Руководство пользователя

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The flashing digit of the display can be changed by
pressing the
Up or Down buttons. When the first
digit is correct, pressing P will transfer control to
the next digit.
When the least significant digit has been adjusted,
press
E to return to the 'ZEro' prompt, from which
the span prompt 'SPAn' can be selected by
pressing the
Up or Down button.Press P to show
the transmitter display at which the output current is
20mA. The flashing digit of the display can be
changed by pressing the
Up or Down buttons.
When the first digit is correct, pressing P will
transfer control to the next digit. When the least
significant digit has been adjusted, press
E to
return to the 'SPAn' prompt.
If a complete loop including a primary element,
BA578C temperature transmitter and a load are
being calibrated, the Trim Menu allows the trans-
mitter display and output current to be adjusted to
compensate for inaccuracies. Details of the trim
menu are contained in section 6 which also
describes periodic calibration.
5.7 Security Code 'COdE'
Access to the Programme and Trim Menus may be
protected by a four digit numerical security code
which must be entered before access is granted.
New instruments are programmed with the default
security code 0000 which allows unrestricted
access to both menus.
To enter a new security code select 'COdE' from
the Programme Menu and press
P which will cause
the transmitter to display the current security code.
Each digit of the code can be changed using the
Up
and Down push-buttons, and the P button to move
to the next digit. When the required code has been
entered press
E to return to the main menu. The
revised security code will be activated when the
transmitter is returned to the display mode.
If the security code is lost, access to the
Programme and Trim Menus can be obtained by
putting the internal security link in the override
position - see Fig 6. The security code can then be
viewed by selecting 'COdE' from the menu and
pressing
P .
To access the security code link un-plug the
removable terminal(s) from the rear of the
instrument by gently pulling, and remove the
instrument rear panel which is secured by six
screws. The link can then be moved to the override
positioned as shown in Fig 6.
Fig 6 Location of security code override link
5.8 Calibrating the internal references
WARNING!
Adjusting the internal references will alter
the instrument performance. Do not
attempt to recalibrate these references
unless you have adequate test equipment
and have read the following instructions.
For routine calibration of the instrument
use the Trim Menu described in Section 6.
If the internal references are used for calibrating
the BA578C transmitter they may require periodic
checking against external voltage, resistance or
temperature standards. Annual checks will produce
acceptable performance, although less frequent
checks are usually adequate.
If the BA578C transmitter is calibrated against an
external voltage, resistance or temperature
calibrator using the Trim Menu, the internal
references should never need re-calibrating.
Details of the Trim Menu are contained in
section 6.
There are four internal references:
Voltage input
3-wire RTD
4-wire RTD
Current output
The input voltage reference must be adjusted first
irrespective of the transmitter application, but it is
only necessary to adjust the other three references
if the function to which they relate is being used.
For example, a BA578C with a thermocouple input
from which the 4/20mA output current is being used
would require the voltage input and the current
output reference adjusting.
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