FLUID COMPONENTS, INTL
CHAPTER 1 - GENERAL INFORMATION
Model ST98 Flow Meter
1 - 2
Doc. No. 06EN003291 Rev. A
Figure 1-2. Cut-Away View Of The In-Line Flow Element Tube
ACTIVE (HEATED) RTD
REFERENCE (NOT HEATED) RTD
Transmitter Electronics
The transmitter electronics convert the sensing element's RTD temperature differential into a flow signal that is
read on a display . The transmitter also produces an analog output flow signal suitable to interface with process
controls. The output is a representation of the amount of flow or temperature present in the process. The flow
output is transmitted on a source milliamp output and / or voltage output. Both the flow output and process
temperature can be displayed on an optional LCD display.
There are 2 kinds of enclosures available for the electronics:
1.
Standard:
Polyester Coated Carbon Steel Rated NEMA/CSA Type 4X (equivalent to IP66) and Division 2 (Ex n), Rating
is pending. (This is a 6 X 6 X 4 Inch Square Enclosure.) (152.4 X 152.4 X 101.6 mm)
2.
Optional:
Aluminum rated for Hazardous Location use Class I and II, Division 1 and 2, Group B, C, D, E, F, G
(previously referred to as NEMA 7 and EEx d IIc) resists the effects of weather and corrosion.
(This is a 4.8 X 9.31 Inch Cylindrical Enclosure.) (121.8 X 236.47 mm)
Instrument Configuration
The instrument can be in integral arrangement (the electronics and the sensing element are combined in one
enclosure), or the instrument can be in a remote arrangement (the electronics and sensing element are in separate
enclosures).
In the case of a remote enclosure, the standard configuration of the sensing element (local) enclosure is an
aluminum rated for Hazardous Location use Class I and II, Division 1 and 2, Group B, C, D, E, F, G (previously
referred to as NEMA7) and EEx d IIC and resists the effect of weather and corrosion. The dimensions are 4.68 X
4.82 inches (119 X 122 mm) and is cylindrical in nature.
In-Line Sensing Element (Flow Tee)
The in-line sensing element is made in the same way as the insertion type of flow element is. To correctly orient
the in-line sensing element, a flow arrow has been etched onto one side of the sensing element.
The in-line flow element is inserted in the process line with the flow arrow pointing in the same direction of flow.
See Figure 1-2 for a cutaway view of the in-line element.
