Pulse dosing as an operation mode has its limitations. From an application perspective it is
often not the most efficient method of achieving concentration consistency due to the
pump only metering when a pulse is received, as opposed to continuously running in
proportion to the flow. Intermittently dosing into a fluid line will require enough pipe to
ensure the solution is adequately mixed, or a mixing tank.
With the ability to operate at very low speeds, metering chemicals is a much better
solution than dosing them at intervals. We recommend examining your process to identify
whether a 4-20 mA signal can be used rather than a pulse. Where technology does not
allow a 4-20 mA signal we recommend using a signal converter accessory. This can be used
to change your pulse signal to a 4-20 mA signal, ideal for metering (see "Analog 4-20 mA
mode (Universal and Un only)" on page 83).
23.3
Fluid recovery mode (Manual, PROFIBUS, Universal and
Un only)
In this operating mode, the pump can be run in reverse for short periods to recover
fluid/chemicals pumped. This is mainly used for maintenance purposes.
Press the
MODE
key, using the
+/-
keys position the selection bar over the fluid recovery
menu option and press
SELECT
.
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