NIVELCO EasyTREK SCD-300 Series, Инструкция по установке и программированию

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5. PUTTING INTO OPERATION, ADJUSTING, PROGRAMMING
5.1. P
UTTING INTO OPERATION
After switching on the correctly wired unit the transducer begins to click audibly. In about 20 … 50 s the ECHO LED goes on and a signal between 4 ... 20 mA
appears on the current output. When first powering the unit, it measures with the standard manufacturer’s settings (see some of the most important parameters
below).
Default parameters
All the transducers get the same factory default parameters that can also be reset later if needed. Some of the most important parameters of the EasyTREK
SCD-300 series can be found below.
⇒
Measurement mode: level (LEV),
⇒
4 mA is assigned to the
X
M
maximum measuring distance (minimum level)
⇒
20 mA is assigned to the
X
m
minimum measuring distance (maximum level)
⇒
Current output holds last value in case of error
⇒
Damping: 300 s
All the other measurement values are set to fit the values suitable for standard tasks. The functions used in special cases are switched off.
A
IMING THE SENSORS
When the material to be measured is being filled or emptied, because of the formation of an angle of repose, the vertically installed transmitter will experience a weak
signal. This can be eliminated in most cases by tilting the unit, so the aiming device is a very important part of these transmitters. The proper aiming can be set and
checked while the transmitter is being used, desirably when the silo / tank is almost empty. Usually it is best that the transmitter points to the middle of the bottom of
the silo/tank.
In cases when the silo is narrow, and the height / diameter value equals to or is more than 5, tilting is
usually not necessary. Aiming should also be checked when the silo / tank is full, because the echo can
be adversely weak even when coming from a nearby surface. This usually happens when the angle of
repose is big. In this case an optimal solution must be found in which the echo coming from any
distance is acceptable. The SERVICE PARAMETERS that can be reached during programming provide
help for set-up. That means that the aiming adjustment and the programming should be done at the
same time.