Fluid Components International MT86, MT86HT Operation

CHAPTER 3 - OPERATION FLUID COMPONENTS INTL

3. Operation

Introduction

The flowmeter has been configured and calibrated to custom specifications. Each flowmeter contains distinct
operating limits and units of measurement. This chapter will show how to determine and manipulate the
configuration of the flowmeter.

Caution:

The flow transmitter contains electrostatic discharge (ESD) sensitive devices. Use standard ESD
precautions when handling the flow transmitter. See Chapter 2, Installation, for ESD details.

Apply Back-Up Battery Power

There is a totalizer option for the flowmeter. This option has a backup battery that keeps power applied to the
memory that holds the accumulated count during loss of power. There is a jumper on the back of the totalizer and
display board that needs to be repositioned to the ON position. See Figure 3-1 for the jumper location. The
estimated life of the battery is 3 years of power off operation. The battery power is drained only when the operating
power is off and the battery power is on. During shipment and storage, the battery jumper is OFF to conserve power.

Apply Power

Warning:

Verify the wiring, then apply power to the flowmeter. There are no special instructions for shutdown of the
flowmeter; just remove the operating power.

Wait a minimum of 5 minutes for flowmeter to stabilize. The display will indicate the current media flow. There are
no operator actions needed because the flowmeter operates from the factory settings.

When an open flowmeter has power applied, the operator assumes all responsibility for
conformance to safety standards and safe practices.

If the display is blank, is out-of-range for the expected values or is obviously not right then turn off the power and go
to Chapter 5 - Troubleshooting, to find the problem.

Operator Interaction

There is little need for interaction between the operator and flowmeter. The flowmeter is fully automatic when it
operates in the monitor mode. Setting the output signal and switch point relay closures as well as other options
depend on individual applications. FCI advises the use of factory default settings that the flowmeter was ordered
with. Do not reset the flowmeter's operating values by trial and error. Standard output options, such as a switch
point relay closure, operate automatically as a function of the output signal level.

A calibration table can be found in the back of this manual. The table shows a listing of the actual mass flow values
as indicated by the output signal. For example: using the standard 4-20 mA output signal, if the signal is 12.0 mA,
find 12.0 in the milliamp row and read across to the next column for the measured flow.

The display provides an instant readout of mass flow. The display shows only the flow rates between the upper and
lower limits of the calibrated range. For zero-based instruments the display will show zero whenever the flow rate is
below the calibrated lower limit. For non-zero-based instruments the display will read the minimum specified
flow rate.

Doc. No. 003162 Rev. F 3 - 1

Models MT86, MT86HT

FLUID COMPONENTS INTL CHAPTER 3 - OPERATION

The flow totalizer accumulates the total quantity of media that has passed the flow element over a specific time.
Short two connector terminals together on the display board to reset the flow totalizer display, see Figure 3-1 for

details. In applications where the operator is required to reset zero, FCI recommends that these terminals be brought
out to a convenient reset switch.

Figure 3-1. Battery Jumper and Reset Locations

Non-Zero Based Calibration

This is a factory preset item.
In a non-zero based calibration, the low-limit output signal (4 mA) is equal to the minimum calibrated flow. The

minimum calibrated flow is a value greater than zero. The flowmeter's output signal will indicate the low-limit flow
signal (4 mA) from zero flow up to the low-flow limit parameter. Use a non-zero based calibration when the
minimum flow rate does not approach zero and the turndown ratios are small.

At no-flow, the minimum customer specified flow rate will appear on the display.

Models MT86, MT86HT 3 - 2 Doc. No. 003162 Rev. F

CHAPTER 3 - OPERATION FLUID COMPONENTS INTL

Zero Based Calibration

In a zero based calibration, the slope of the output signal is shifted so the low-limit flow output signal (4 mA) is
equal to zero flow. See Figure 3-2 for details. Flowmeters cannot measure zero flow accurately. The flowmeter will
readout the low-limit signal (4 mA) from zero flow up to the minimum calibrated flow. Then the output signal will
step up to the proper signal value of the mass flow.

The output signal is easier to interpolate when milliamp output is interfaced with control room 0 to 100% gauges;
50% of the signal will correspond to 50% of the maximum flow rate.

Zero based flowmeters have less signal to resolve over full scale. A zero based flowmeter with a turndown ratio of
10:1 will have 10% less output range to resolve flow (5.6 mA to 20 mA instead of 4 mA to 20 mA in a non-zero
based flowmeter).

Delta "R" Table

The actual data chart for this particular flowmeter can be found in the page protector at the back of this manual. The
Delta "R" part of this sheet gives the factory calibration measurement points of the Delta "R" differences between the
REF and ACT RTDs at certain flow rates. These measurements used by the factory determine the linearization
coefficients that are applied over the desired flow range. The corresponding current and voltage output readings are
also shown for the factory default settings.

The flow versus Delta "R" relationship is fixed for a given set of sensing points. There is a lookup table that is in the
page protector in the back of this manual. It is a printout of factory default settings for zero and offset readings. The
table shows the relationship between the displayed mass flow readings as they are related to the current output. The
output is calculated over the entire flow range with the use of a fitting equation and its respective coefficients.

The Delta "R" Table has a great deal of useful information. The table can be used to verify the correct operation of
the flow transmitter without the flow elements connected. By using the Delta "R" Table the flow element sensing
points are simulated with precision resistors or decade boxes.

Figure 3-2. Zero Based Calibration

Doc. No. 003162 Rev. F 3 - 3

Models MT86, MT86HT