Table of Contents
Advertisement
TRANSMITTER TERMINOLOGY
The Communicator primary use is the commissioning
and the servicing of Smart transmitters. The commis-
sioning includes all the operation of functional testing of
the transmitter and check of the transmitter configura-
tion data normally performed before the putting in service,
while the servicing is for operation after installation.
Commissioning can be done either in the field or on the
bench.
The advent of smart microcontroller-based transmitters
brings new procedure and terminology to the instru-
mentation field, not present in the days of pure analog
transmitters. This manual would like to present the
following terminology to define some of the operations
of commissioning as follows:
- Ranging - Setting either or both the lower and upper
value ( LRV & URV ) thereby determining the zero and
span by user entry of the numeric values. This operation
is available to the user via the CONFiguration menu.
Also called "Dry Calibration".
- Reranging - Setting either or both the lover and upper
range values ( LRV & URV ) using the value of the
applied pressure or input reference. This operation
requires accurate test equipment. This operation is
available to the user via the RERANGING function
under the TRIMming menu. Also called "Wet calibration".
- Trimming - Performs small corrections to either the
sensor measurement value or the analog output value
( i.e. corrections to either the input or output sides of the
transmitter's microcontroller ). Major detail on this ope-
ration can be found in the "Use of the green keys-TRIM"
section of this manual. This operation requires accurate
test equipment. This operation is available to the user
via the SENSOR TRIM and the 4-20 mA TRIM under the
TRIM menu.
Consideration on accuracy
The use of a sensor having a good intrinsic linearity and
repeatability and the possibility to compensate, using a
microprocessor, the residual non linearity errors and the
errors due to the influence of the temperature and static
pressure leads to an instrument having a very high
accuracy.
The factory final calibration of the transmitter is done
using testing equipment having an accuracy from four
to ten times the specified accuracy of the transmitter.
This facts bring to the consideration that, unless your
testing equipment is of a suitable class ( accuracy three
times of the transmitter accuracy ), a calibration done
using the Ranging procedure leads to results that are
surely better that a calibration done using poor quality
testing equipment.
Before to decide about the type of calibration to perform
it is then to check the transmitter accuracy stated in the
specification sheet and the accuracy of the testing
equipments available.
- 8 -
GENERAL OPERATIONS
Battery Charging
There are four nickel-cadmium rechargeable batteries:
the expected working time of the Communicator with
the battery full charged is about 10 hours. When the
battery is nearly 90% gone, i.e. 1 working hour is still
available, a low battery warning signal, (
in the lower right corner of the LCD display.
The Non-Volatile EEPROM ( which is used to store
database configurations ) is not affected by a low
battery voltage or battery replacement.
The battery pack has an expected life of 1000 charge/
discharge cycles. This expectancy is valid if the charge/
discharge cycles are properly performed. Nickel-cad-
mium batteries require that they are nearly fully dischar-
ged before recharging, therefore the user should wait
for the low battery indication before recharging.
DANGER - Do not use the battery charger in areas
classified as HAZARDOUS LOCATIONS. This can
results in HAZARD OF FIRE AND EXPLOSIONS.
The battery charging should be done using the battery
charger optionally supplied with the Communicator.
Use of other chargers is discouraged but can be used.
Under such conditions, it should be noted that the
maximum charging current be less than 50 mA. If a
constant voltage charger is used the voltage must be
7.5 Volt D.C. The full charge of the battery pack requires
about 12/15 hours.
Access to the battery charging connector is by removal
of the cover plate located at the top of the Communica-
tor. The connector is a 5.5 mm plug with the center
contact being positive (+) and the outside contact being
nagative (-).
CAUTION - Do not maintain the battery charger
connected for more than 15 hours: the battery pack
and the internal circuit may be damaged.
Battery pack replacement
The battery pack consists in a plastic box containing the
Ni-Cd battery and all the necessary intrinsic safety
protection diodes and resistors. The plastic enclosure
is completely filled with silicon resin to prohibit access
to the components.
DANGER :
Do not remove the silicon
protection, don't change or modify intrinsic safety
components. This can cause HAZARD OF FIRE
AND EXPLOSIONS.
L
) is displayed
B
resin
Hide quick links:
Advertisement
Table of Contents
