Hastings Economy Vacuum Gauges, Models VH-3 and
VH-4, are stable, dependable instruments for less demanding applications.
These modular gauges feature solid-state construction with a taut-band
meter and provide rapid response. The gauge tubes have excellent
stability and ruggedness and provide pressure measurements over
the 0-5 and 0-50 Torr ranges. Dual-scale meter faces also provide
millibar readings. Environmental tests show that the gauge tube
is stable over a wide temperature range. The instruments are relatively
free of cable-length effects, permitting changes of cable length
up to 25 feet without readjustment or recalibration.
Hastings
VH-3 and VH-4 Vacuum Gauges use a noble metal thermopile circuit. The hot
junctions of the thermopile are heated directly by an AC current, while
an equal number of cold junctions are kept at ambient temperature by heavy
mounting studs. Thus a DC voltage is generated between hot and cold junctions.
As the pressure decreases, the lowering of the thermal conductivity of the
gas surrounding the hot junctions tends to increase the temperature of the
hot junctions, thus increasing the output of the thermopile.
Vacuum
Controllers
Hastings Economy Vacuum Controllers, CVH Models, are fully automatic, continuous-reading
instruments for less demanding applications. These modular instruments provide
dependable control with simplicity and economy. The gauge tubes have excellent
stability and ruggedness and provide pressure measurements over the 0-5
and 0-50 Torr ranges. Dual-scale meter faces also provide millibar readings
Providing control throughout the entire scale, the adjustable control arm
is set with the pointer at the pressure desired. When the indicating needle
passes the set point, the relay is activated. The needle continues to indicate
pressure while it passes below the set point. When the indicating needle
passes above the set point, the relay automatically drops out but the needle
continues to indicate pressure throughout the entire range. Control is positive
and without chatter.
Installation
Accessories
Hastings Instruments offers a complete line of system attachments allowing
for easy maintenance and contamination resistance operations. Gauge tubes
are offered with various system fittings to match almost any system attachment
requirement. Addition-ally, Hastings’ complete line of quick disconnect
attachments allowing customers to install these special fittings once and
then easily replace sensors without vacuum sealant or tape. For particularly
dirty systems, Hastings offers a particle drop-out trap containing a series
of nine separate baffles which prevent solid contaminants from having a
direct path to the sensors thermopile.
Calibration
Reference Tubes
The Hastings Reference Tube is an evacuated, sealed vacuum gauge tube accurately
calibrated to precisely simulate a gauge tube at a given operating pressure.
It permits quick and easy recalibration of Hastings Vacuum Gauge Indicators
by merely plugging the instrument into the reference and adjusting the calibration
“current set” potentiometer until the instrument reads the exact
pressure noted on the reference.
Hastings Reference Tubes employ the same Hastings noble metal thermopile
used in all Hastings Vacuum Gauge Tubes. The thermopile is sealed in a glass
capsule that has been evacuated, baked, outgassed, sealed, and then aged
to ensure stability over long periods of time. The sealed capsule is then
housed in a protective metal shell to provide a rugged, trouble-free assembly.
Specifications
Power
E Option
115 VAC 50/60 Hz
230 50/60 Hz
Cables (approx.)
6-ft power cable and 8-ft. sensor
cable attached.
Extensions available.
Weight (approx.)
3 lb max (1360 g)
(varies by model)
Relays (CVH units)
115 V, 5 A SPDT @ 115 VAC non inductive.
Normally open and normally closed.
DIMENSIONS (Reference
only)
VH
CVH
4.120 (W) x 3.500 (H) x 3.000 in.
(D) (10.40 x 8.89 x 7.62 cm)
5.000 (W) x 4.187 (H) x 7.000 in. (D) (12.72 x 10.62 x 17.82 cm)
STANDARD METAL
GAUGE TUBE
Overpressure
50 psig max.
Material of Construction
Nickel-plated steel,
stainless steel, glass, noble metal thermocouples.
