Fluid Components International MT91 Glossary

APPENDIX B - GLOSSARY FLUID COMPONENTS INTL

Appendix B. Glossary of Terms

Area

Bipolar

DVM

EIA

C1 - C5

Comm Mode

CorrF[1] - [4]

Cross-sectional area for a process line or duct.

2

Area of a circular duct= p r2 or p

I.D.

()

2

Area of a Rectangular duct = h w×

Allows users to view both negative and positive values for DR.

Digital Voltmeter

Electronics Interface Association

C1 through C5 are flow coefficients for the balanced polynomial equation. The
flow coefficients characterize the shape of the curve generated by the equation.

22

=++++

Flow C R C R C C R C R

−

∆∆ ∆∆

12345

( ) () () ( )

C1- C5 are unique to each sensing point. On the Delta R Paramter sheet,
they are shown as H01C1 through H01C5 for sensing point 1. (H = head,
01 = sensing point 1).

Serial communication mode. There are three options: EIA-232, EIA-422, EIA-

485.

CorrF[1] through CorrF[4] are correction factors that apply to the Corrected Flow
Rate equation. See Chapter 3 - Operation for more information.

dR Min

dr Max

Flow Element

Flow Factor

Flow Min

Flow Max

Flow Transmitter

Full Scale

Corrected Flow Rate = C1+×+×+×()()()Cm Cm Cm

20 30240

3

DR value low end cutoff. Should be set to approximately 5 ohms less than the
lowest calibrated DR.

DR value high end cutoff. Should be set to approximately 5 ohms greater than the
lowest calibrated DR.

The Flow Element includes the local enclosure and the sensing points.

The Flow Factor is the multiplier that converts the internal flow rate (SFPS) to the
user selected flow untis.

Minimum calibrated flow rate in standard feet per second (SFPS)

Maximum calibrated flow rate in standard feet per second (SFPS)

The Flow Transmitter consists of the remote enclosure and all of the electronics
contained within.

Full scale is from the zero value to the max flow value. For zero based
applications this is from 0.00 to the maximum flow value. For non-zero based
applications full scale is from minimum flow value to the maximum flow value.

Offset 1 - 16

Doc. No. 003185 Rev. B B - 1

Offset value for each sensing point. Offset Equation = DR + Offset Value

Model MT91 Multipoint Flowmeter

FLUID COMPONENTS INTL APPENDIX B - GLOSSARY

Port [1]

RTD

Span

Standard Density

Sensing Point

DD

DR

DD

DD

DT

DD

Unipolar

Zero

Channel 1 for output signal. Port [2] corresponds to Channel 2.

A Resistance Temperature Detector operates on the principle of change in
resistance as a function of temperature.

Span is the full scale value minus the minimum flow value.

Standard Density is the density of media (customer’s original request) at standard
conditions usually at 14.7 PSIA and 70°F: used by firmware for conversion when
a mass flow rate unit is chosen such as LB/HR etc.

The Sensing Points contain the four thermowells that house the resistance
temperature detectors and the heater.

The difference between two resistance values.

The difference between two temperature values.

Allows users to view only positive values for DR.

0.00 for zero based applications. For non-zero based applications the zero is at
minimum flow.

Model MT91 Multipoint Flowmeter B - 2 Doc. No. 003185 Rev. B