ACCURACY: +/-
3% from 20-50% of scale and +/- 2% over remaining 50% of scale.
CASE SIZES: 2, 2½, 3½, 4½ inches
diameter.
CASE MATERIAL: Steel
with black enamel paint.
CASE STYLE:
U = Front Flange (U-Clamp), flush mount with center back
remote connection.
(2", 2½", 3½") = Marshalltown X-8.
FF = 3 Hole Front Flange, flush mount, with center back remote
connection.
(2", 2½", 3½") = Marshalltown X-5.
G = Back Flange, surface mount, with adjustable lower back &
bottom remote connection.
(3½", 4½") = Marshalltown X-6, X-7.
P = Plain case (3½" only) with adjustable angle, bottom
direct mount (without capillary) = Marshalltown X-3.
TUBE: Drawn
copper alloy.
MOVEMENT: Brass
sector with polycarbonate side plates.
CAPILLARY: 6
feet of flexible capillary with double-braided copper with sheath
standard.
CONNECTION:
CB = Center back remote ½" NPT connection, (FF & U
cases).
BB = Back & Bottom (Dual) adjustable remote ½" NPT
connection, (G case)
BA = Bottom Adjustable Angle direct mount ½" NPT connection.
Without capillary. (P case) = (Marshalltown X-3)
BULB: 2½" sensing bulb standard.
Cases 2½". 3½", 4½" have ½" union nut standard.
RANGES: Six
standard ranges DUAL SCALE in degrees Fahrenheit & Celsius.
- 40ºF to 60ºF / - 40ºC to 15ºC
- 40ºF to 120ºF / - 40ºC to 50ºC
0ºF to 120ºF / - 15ºC to 50ºC
0ºF to 180ºF / - 15ºC to 80ºC
30ºF to 240ºF / 0ºC to 115ºC
50ºF to 350ºF / 10ºC to 175º
DIAL STANDARD: Dual Scale Standard degrees
Fº and Cº.
DIAL COLOR: Black
markings on white.
POINTER: Standard
Pointer.
WINDOW: 2",
2½", 3½" have twist-in Clearlok window. 4½" case has
dimpled ring and acrylic window.
OPERATING PRINCIPAL:
A vapor actuated thermometer is essentially a pressure system with
a sensing bulb at one end connected by a capillary to a pressure gauge at
the other. The bulb is filled with a liquid which vaporizes as the
temperature rises. This causes the pressure in the gauge bourdon tube to
rise and move the pointer to indicate the measured temperature.
This temperature-to-pressure relationship is non-linear which means
that the graduations on the line end of the scale are close together,
whereas the graduation on the upper end are spaced farther apart. Changes
in ambient temperature along the capillary or at the scale do not affect
the thermometer readout. This means that capillary up to 75' long can be
used without the need for ambient temperature compensation.