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In October, SeaMetrics began shipping an upgraded
version of the FT420. The upgrade was originally done for internal
manufacturing purposes, so that we could shorten delivery times.
However, in the process we were able to make some other worthwhile
additions to features.
One of the main improvements is the change to
a relay pulse output. In the past, relay output had to be ordered
as an option. Now it is a standard feature. Another big improvement
is the built-in choice of time base. Now, the rate reading can
be in units such as gallons per day or liters per second.
Time base readout
A less-obvious feature is a flow
alarm setpoint. This is accessed by special keystroke, and can
operate as either a minimum flow or a maximum flow alarm. The
relay output (which is used for pulse output if the flow alarm
is not being used) becomes energized when flow rises above or
falls below the setpoint.
Another slight change makes it easier to power
the FT420 with a Liquid Metronics chemical metering pump. Those
of you familiar with these pumps know that LMI puts a small 12
VDC power supply in the pump circuitry. The revised FT420 allow
the user to set the 20 mA point ("SET 20") to zero. When this
is done, power consumption of the FT420, with sensor attached,
is 4 milliamps. This is well within the limits of the LMI power
supply. One cable connected to the pump can both power the FT420
and supply a pulse to externally pace the pump.
These features are just a bonus. The new design
meets the objective of allowing quicker delivery, which should
become more evident during high-volume times of year. It is also
more reliable. We have tested it under a variety of extreme conditions
and are very pleased with its ruggedness.
The FT420 upgrade is one of the first projects
of our new electrical engineer, Venko Gyokov, who joined us from
Bulgaria. Venko has many years of experience in designing high-reliablity
products, and we look for good things from him in the future.
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