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Nick -
The VMS1000 oil and fuel pressures were
designed for the Honeywell MediaMate, which produces 50mV DC full-scale
output when excited with 5VDC. The MediaMate, however, is inferior,
antiquated technology and outrageously overpriced.
A modern, high-quality replacement is the
Measurement Specialties US321. It also produces
50mV DC when excited with 5VDC; hence, it's an electrically-DIRECT
replacement for the MediaMate http://www.meas-spec.com/downloads/US300.pdf
A problem, however, is that the
VMS1000's combination of 5VDC excitation and 50mV DC full-scale output is,
apparently, rarely used in industry; hence, I couldn't locate any US321's -in
the needed pressure range- for sale despite an exhaustive search. I
contacted Measurement Specialties last August and learned that they would
manufacture them at a cost of $140 each, with a minimum order of five. So I
ordered five @50 psi (fuel pressure for fuel-injected engines) and five @100 psi
(oil pressure). I ordered them with four foot pigtails to allow direct
routing to the DPU, with no intermediate connector. Attached is a photo of them
installed on my engine. If anyone is interested, I'm offering the extra's for my
price of $140 each.
Bill Rumburg
N403WR (Sonic bOOm)
Hello Everyone,
A few weeks ago we had a discussion about this, and I then went away and
checked my installation. After measuring the voltages I concluded that the
display unit is ok, but both the Oil Pressure and Fuel Pressure sensors are
not behaving.
So then I looked into replacements. There was an interesting post last
September from Bill Rumburg about using sensors from Measurement Specialities;
the originals are Honeywell Mediamates.
Bill was saying the OP and FP transducers are different in their voltage
vs pressure response by a factor of 2 and he was exploring some alternative
devices. But here is another idea. Why not just find a sensor that gives the
correct output for FP? The same sensor will give 2x the reading if used for
OP, but that can be scaled down by 2 with a simple precision resistor
network.
If that is correct, and I’ve followed the previous discussion correctly,
then Digi Key have the very item we need:
What do you think, people?
Yours,
Nick
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