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Converter Specifications
Output signals
• Density (consistency) measurement output:
4-20mAdc (load resistance 750 ohm maximum,
isolated output.)
• Density (%TS, consistency) fault or
Maintenance signal:
125Vac, 0.1A (resistive load) solid state contact;
opens when an error occurs in the converter or
when the LQ500 is in the setting change mode,
otherwise the contact remains closed.
• Communication signal:
Digital signal is superimposed on 4-20mAdc
current signal (conforming to HART protocol (*1)).
Load resistance: 240 to 750 ohm
Load capacity: 0.25µF maximum
*1 HART (Highway Addressable Remote Transducer)
protocol is a communications protocol for industrial
sensors recommended by HCF (HART
Communication Foundation).
Note: The optional BF100 configurator can be used to
operate the LQ500 from remote places by
connecting the communication cable between the
LQ500's 4-20 mA dc output signal lines.
Input signals
• External synchronized input signal:
In order to avoid problems of density (%TS,
consistency) measurement such as
inhomogeneous condition caused by
discontinuous process operation and empty pipe
condition caused by stopping process operation.
<Specification>
One dry "make" contact;
Contact capacity of approximately 5Vdc. 0.1A is
required. This contact signal can be used to start
or stop density (consistency) measurement in
synchronization with an external contact, such as
the contacts on a pump.
The measurement starts or stops as follows:
Contact closed: Starts density (%TS,
Contact open: Stops density (%TS, consistency)
consistency) measurement.
measurement.
• Density multiplier switching signal:
In order to achieve selecting up to 4 kinds of
liquid concentration measurement independently
as maximum.
<Specification>
Two voltage signals described below are required:
Input voltage: H level: 20 to 30 Vdc
L level: 2 Vdc or less
Input resistance: Approx. 3k ohm
• Internal conductivity correction function:
This function reduces the influence (density
variation) of the conductivity changing by using
the measured valve of LQ500. Thus, this function
does not need to input the conductivity meter
signal (the correction factor of this function is
calibrated with sodium chloride). If this function
(Internal conductivity correction) does not reduce
the density variation by the conductivity changing,
you can use "External Conductivity correction".
• External conductivity correction function:
Conductivity correction signal:
Needs to prepare an additional conductivity meter
when using this function. Install in where is able
to have a stable and accurate measurement.
<Specification>
Input signal: 4 to 20mAdc
Conductivity range: 0 to 10mS/cm
Update period for density (%TS, consistency)
measurement output and display: Approx. 1 second
Functions by software as standard:
• Data saving function:
In order to save measurement data into the
memory of converter temporary.
The oldest data is overwritten.
<Specification>
Data storage points: 256 points maximum.
Period: 1 to 1,800 minutes (1 minute each).
ex 1: The data is saved for approx. latest 4.26
hours when programming every minute.
ex 2: The data is saved for approx. latest 21.3
hours when programming every 5 minutes.
LQ500
EJL-106J
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