Scott Fetzer meriam MFT 4000 Series Assembly instructions

File No. 4000:440-5
August 2003
MFT 4000 Calibrator
MFT 4010 Calibrator with HART®
MFT 4020 Calibrator w/Loop Power Supply
OPERATOR
INSTRUCTION MANUAL

MFT 4000 SERIES OPERATOR INSTRUCTION MANUAL
Models
MFT 400X Modular Calibrator
MFT 401X Modular Calibrator / HART®Communicator
MFT 402X Modular Calibrator / Loop Supply
IMPORTANT NOTICE
ASSISTANCE
For customer assistance please contact the local Meriam Representative or Meriam Process Technologies
directly. For a geographic listing of Representatives and their contact information, visit our web site at
www.meriam.com and click on the “Representatives” button. Contact Meriam Process Technologies
directly by phone at [phone] or by e-mail at [email protected]m. Direct all assistance inquiries
to Technical Services.
HART is a registered trademark of the HART Communicator Foundation
MERIAM PROCESS TECHNOLOGIES
10920 Madison Avenue
Cleveland, Ohio 44102
TELEPHONE: [phone]
FAX: [phone]
E-mail: [email protected]
Web Site: www.meriam.com
Important information on the product is contained in this
manual. Read this manual carefully and completely before
operation the product. For the safety of the operator and the
system, a thorough understanding of this manual is necessary
before commissioning, using or maintaining the product.

MFT 4000/4010/4020 OPERATING INSTRUCTIONS
TABLE OF CONTENTS
Subject Page
MFT 4000 Overview.................................................................................................................................. 1
Keypad Overview ...................................................................................................................................... 1
Single Function Keys............................................................................................................................ 1
Dual Function Keys .............................................................................................................................. 2
Soft Keys............................................................................................................................................... 3
Alphanumeric Data Entry ..................................................................................................................... 3
Measure Mode ........................................................................................................................................... 5
Header-line Symbols............................................................................................................................. 5
Display Screen ........................................................................................................................................... 5
Soft Key Options........................................................................................................................................ 5
Zero....................................................................................................................................................... 6
Mn/Max ................................................................................................................................................ 6
Damp..................................................................................................................................................... 6
More...................................................................................................................................................... 6
Hold ...................................................................................................................................................... 6
Sensr...................................................................................................................................................... 6
Rcal ....................................................................................................................................................... 7
Settings....................................................................................................................................................... 7
Lockout Features................................................................................................................................ 7
Lockout Code................................................................................................................................ 8
Disable Lockout ............................................................................................................................ 8
Change Lockout Code................................................................................................................... 8
Damp Rate ......................................................................................................................................... 8
Off Timer ........................................................................................................................................... 9
Clock Edit .......................................................................................................................................... 9
General Operation.................................................................................................................................... 10
Sensor Installation/Removal ............................................................................................................ 10
Change Units / Removing & Restoring Sensors on Display............................................................ 10
Sensor Module Engineering Units ................................................................................................... 11
Installation & Removal of Batteries – Standard MFTs.................................................................... 11
Install & Remove Batteries – Intrinsically Safe MFTs.................................................................... 11
Over pressurization – Pressure Modules.......................................................................................... 11
Media compatibility – Pressure Modules......................................................................................... 12
Applications ............................................................................................................................................. 12
Gauge Pressure Calibration.................................................................................................................. 12
Differential Pressure Calibration ......................................................................................................... 13
Additional DP Application Information .............................................................................................. 14
Vacuum and Absolute Pressure Calibration ........................................................................................ 14
Electrical Connections ............................................................................................................................. 15
Milliamp transmitters............................................................................................................................... 15
Voltage transducers.................................................................................................................................. 16
Field Recalibration.................................................................................................................................. 16
DB-9 Connection Port.............................................................................................................................. 19
Hazardous Area Use (Intrinsically Safe Option) ..................................................................................... 19
MFT 4000 Series - Model Specific Features ........................................................................................... 21

TABLE OF CONTENTS
Subject Page
MFT 4010 with HART®Communications ...............................................................................................21
HART Commands ................................................................................................................................22
HART Connections...............................................................................................................................22
HART Communications .......................................................................................................................23
Communications Trouble Shooting .............................................................................................23
Multidrop Polling.........................................................................................................................24
HART Offline Mode.............................................................................................................................24
List/Show DOFs...........................................................................................................................24
List/Edit Configs .........................................................................................................................24
Create Configs.............................................................................................................................25
Delete Configs / Clearing Config Memory .................................................................................25
HART Online Mode .............................................................................................................................26
Device Configuration............................................................................................................................27
Pressure Trim ........................................................................................................................................32
Analog Trim..........................................................................................................................................35
Loop Test ..............................................................................................................................................37
Scaleable D/A Trim ..............................................................................................................................38
Basic Info ..............................................................................................................................................40
HART Output........................................................................................................................................41
Diagnostics............................................................................................................................................43
Review/Edit...........................................................................................................................................44
Quick Menu ...........................................................................................................................................44
Calibrate Key .........................................................................................................................................45
Quick Cal.....................................................................................................................................47
Smart Trim...................................................................................................................................48
4 mA Analog Trim ................................................................................................................48
20 mA Analog Trim ..............................................................................................................49
Zero Trim...............................................................................................................................50
Lower Sensor Trim................................................................................................................50
Upper Sensor Trim ................................................................................................................50
View Results................................................................................................................................51
Clear Cal Memory................................................................................................................................ 52
More Status Message ............................................................................................................................52
MFT 4010 Device Specific & Generic HART Comm..............................................................................53
Download Site Information – DOFs, Firmware, Utilities.........................................................................53
Who may use.........................................................................................................................................54
PC Requirements ..................................................................................................................................54
Preparing the MFT for updating ...........................................................................................................54
Preparing to Download .........................................................................................................................54
Using the Download Site ......................................................................................................................54
Subscriber Options................................................................................................................................55
MFx Installer Utility .............................................................................................................................55
MFT 4020 Loop Power Model .................................................................................................................56
Connecting the MFT 4020 for Loop Power only..................................................................................56
Connecting the MFT 4020 for Loop Power and 4-20mA meas............................................................57

Documenting Calibration Results .............................................................................................................58
Entering Calibration Documentation Mode..........................................................................................59
Manual Procedure Calibrations and Documentation ............................................................................60
Stored Procedure Calibrations and Documentation ..............................................................................62
Stored Procedure Status Indicators .......................................................................................................65
Deleting Files and Clearing Calibration Memory.................................................................................66
Documenting HART Configurations........................................................................................................67
Returning the MFT for Repairs.................................................................................................................67
APPENDIX
MFT Specifications ..............................................................................................................................68
MFT Models, Options, Ordering Information ......................................................................................69
Sensor Modules List .............................................................................................................................70
MFT Accessories List ...........................................................................................................................70
RTD1000 RTD Measurement Module Instruction ...............................................................................72
TIO0110 T/C Measurement Module Instruction ..................................................................................79
VMA0055 Voltage and Current Module Instruction ............................................................................84
Intrinsic Safety Control Document .......................................................................................................91
HART Command Structure Menu Tree Examples ...............................................................................92

1
MFT 4000 SERIES OVERVIEW
The MFT 4000 Multi-Function Tester (MFT) is a modular calibrator with three sensor bays accommodating
up to three independent pressure, temperature or special function modules. The base MFT incorporates a
voltage and current meter, several keys for user interface and will display up to four measurements
simultaneously. The MFT 4010 adds HART communication capability to the same handheld base unit for
greater flexibility and versatility in commissioning, reconfiguring, and maintaining HART field devices. The
MFT 4020 is a calibrator with integral 24Vdc loop power supply. This feature provides loop power directly
from the MFT.
Note: For Intrinsically Safe MFT models, consult the Hazardous Area Use section of this manual for
specific details on use of approved MFTs and applicable restrictions.
KEY PAD OVERVIEW
The following is an overview of the MFT 4000 series keypad operations. The MFT keypad has three basic
key types (the functions of each are described below): Single function keys, dual-function keys, and soft
keys. Single function keys control a dedicated MFT function. Dual-function keys, through the use of the
Shift key, control two separate functions. Soft key functions change depending on the operating mode. Their
definitions are displayed at the bottom of the LCD, just above each white soft key.
Single Function Keys
On/Off
Pressing the On/Off key powers up the MFT. As the unit powers up, it performs an internal
diagnostic check of its systems. Any abnormalities are posted on the display. The unit will briefly
display the MFT model number and the installed sensor module ranges and bay locations (S1, S2, or
S3) before the unit enters the Measure Mode.

2
Measure Mode
Pressing the Measure Mode button will instantly return the unit to measure mode from any menu or
sub-menu. Measure will appear on the upper left of the display.
Display Contrast
This key allows the user to adjust the contrast of the LCD display for user conditions or preferences.
Pressing and holding this key will cycle through all available contrast settings. If the display is faded
or blacked out, simply depress the key until the display returns to an acceptable level. After
adjusting Contrast, wait at least five (5) seconds before turning unit off to insure storage of new
contrast setting.
Shift
The Shift key must be pressed to access the functions labeled in blue on the dual-function keys.
Pressing the Shift key will allow the user to access and/or alter the corresponding properties. Shift
remains on until it is depressed again. When the Shift key is active, an up arrow ↑ will appear at the
top of the display left of the battery power or AC wall plug icon.
Dual Function Keys
Units Sensor1
The Units Sensor1 key changes the engineering units for
the module in sensor bay 1. The Shift key
must be active before the units can be changed.
HART Active only with MFT 4010
The HART key puts the MFT 4010 series calibrator into its HART Communications mode and
initiates an attempt to establish communications via the HART connections at the bottom of the
MFT.
Units Sensor2
The Units Sensor2 key changes the engineering units for
the module in sensor bay 2. The Shift key must be active before the units can be changed.
Settings
Provides access to the settings menu. This menu shows the current unit settings and allows the user
to customize MFT settings. See Settings section for more details.
Units Sensor3
The Units Sensor3 key changes the engineering units for the module in sensor bay 3. The Shift key
must be active before the units can be changed.
Quick Menu Active only with MFT 4010
This key provides the user with a list of frequently used HARTconfiguration and maintenance
function menus. User can quickly scroll to any desired menu.

3
Units mA / V
Toggles between voltage, current (mA), and off display for the integral voltage and current meter.
This measurement is designated by “V/I” on the display.
Calibrate Active only with MFT 4010
This key enters the MFT into calibration mode for HART device calibrations.
Soft Keys
SOFT KEYS (unlabled)
The four white keys located below the display are soft keys. The specific
functions of these keys change depending on the operating mode of the MFT. Current defintions are
displayed at the bottom of the LCD display.
Alphanumeric Data Entry
Alphanumeric Entry: For application of the MFT requiring alpha and numeric entry (examples: tagging or
messaging), the MFT uses three display grids, the SHIFT key to change from one grid to another, and four
soft keys used for cursor movement and selection of characters and text. MFT and HART communication
functions that require alpha and numeric entry automatically call up the appropriate grid and make the other
grids accessible using the SHIFT key. Row and Column soft keys are used to move the flashing cursor
through the displayed grid. The Select soft key enters the indicated character in the text line and the Done
soft key accepts the displayed text line and returns the MFT to service.
Character grids are provided for numeric, alpha, and symbol characters to permit complete editing of text
fields. Each grid includes back space (←), forward space (→), delete (del) and space (spc) operators to
accommodate text editing needs.
User Interface
The displays shown below illustrate the alphanumeric entry grids and soft key functions. Pressing the
MFT’s SHIFT key changes the display from one grid to another allowing text messages to be developed
using all three grids when needed.
Alpha entry grid Numeric entry grid Symbol grid
HART
Tag No PT-3456
@ [ \ ] ^ _ “
” # $ % ( ) ’
& * + −./ :
;< = > ? , !
−−> <−− del spc
PT−3456 OUTPUT < 50% @_
Row Col Select Done
HART
Tag No PT-3456
A B C D E F G
H I J K L M N
O P Q R S T U
V W X Y Z −.
−−> <−− del spc
PT−_
Row Col Select Done
HART
Tag No PT-3456
1 2 3
4 5 6
7 8 9
.0 + −
−−> <−− del spc
PT−3456_
Row Col Select Done

4
When using any character grid, pressing Row or Col and releasing the respective soft key moves the flashing
cursor one character across or down the gird. Pressing and holding the Row or Col key causes the cursor to
advance down or across, respectively, at a regular rate. Releasing the key when the cursor is under the
desired character stops the cursor movement and allows the selection of the character using the Select key.
Press the Done soft key when the character string is completed to enter the string and continue MFT
operations.
Numeric Entry: Many HART functions require only numeric entry. For these functions the MFT uses an
Increment and Decrement scheme to change the input field one place at a time. Press the Inc / Dec soft keys
to move through a scroll of -, . , 0, 1…9, and space until the desired value is displayed. Press the Next soft
key to enter that value and advance to the next place in the input field. Repeat as necessary. Press the Done
soft key to end the numeric entry session.
Numeric Only Entry Screen
HART
3051: PT-3456
Output:
6.5_ mA
Inc Dec Next Done

5
MEASURE MODE
After the MFT performs its power up diagnostics and displays the model number and sensor data, it defaults
to the Measure Mode. The word Measure appears on the upper left of the display, confirming this mode is
active. The soft key definitions in this mode are directed toward measurement and information functions.
Header-line Symbol Key (see location at right)
heart symbol indicates active HART communication
uup arrow indicates SHIFT key is on
• battery symbol indicates MFT under battery power;
filled portion indicates remaining battery
electrical plug symbol indicates the AC adapter
(P/N A36742) is connecting and powering the MFT
BUSY text box replaces either power symbol when
the microprocessor is busy executing requested tasks
NOTE: Power icons may temporarily disappear during certain HART Communication operations
DISPLAY SCREEN
The display screen displays measurements from modules installed in sensor bays S1, S2, and S3 and displays
inputs to the MFTs voltage or current jacks. Only installed and active sensors are shown. Measurements are
identified on the display by lines with “S1”, “S2”, and “S3” designators for sensor modules and by “V/I” for
analog measurements. The measured values are shown with the corresponding unit of measure.
Measure Mode Main Screen
SOFT KEY MENU OPTIONS
On the bottom of the main menu screen in Measure Mode the following definitions are displayed just above
the white soft keys.
These definitions indicate the current function of each soft key.
BUSY
Hart u
3051: PT-19C

6
Zero
Pressing the soft key corresponding to Zero will zero the installed sensor modules and integral mA/Volts
meter. The LCD will display “Zero in Progress” as this function is carried out. The sensors should be
zeroed prior to making measurements to provide an accurate zero reference. Make sure that no physical
signal is applied to the MFT when performing this function. To prevent unintentional zeroing, a Zero
command will be aborted if more than ±5% of full scale signal is being measured by any MFT sensor.
Absolute pressure modules cannot be zeroed until the applied pressure is less than 5% of full scale. This
prevents the accidental corruption of the absolute zero reference essential to absolute pressure module
performance.
Mn/Max
The Mn/Max key allows the user to display the minimum and maximum measured value each sensor has
measured since this function was activated. The min/max values are displayed below the normal pressure or
V/mA reading. To reset the Mn/Max function, toggle the Mn/Max key off, and then press it again to turn it
on.
Damp
Pressing the Damp soft key initiates an exponential averaging function for the measurements over a selected
time constant. This function smooths over the peaks and valleys of pulsating measurements for a more stable
display. The factory default setting for Damp is 0.5 second. A D symbol appears in the top of the LCD
display when this feature is active. To change the damp rate refer to the Settings section.
More
This option takes the user to more soft key menu options.
After pressing More from the menu options above, the following soft key options are made available:
Hold
Pressing the Hold button freezes the measurements on the display to allow convenient reading or
transcription of data. An H symbol appears on the top of the LCD display when this feature is active.
Pressing Hold again returns the MFT to normal Measurement Mode.
Sensr
Pressing the Sensr key provides detailed information about the installed modules. The first screen provides
information pertaining to the sensor in module bay 1, including the sensor model, serial number, and the date
the unit was last calibrated.
Pressing Next consecutively scrolls through the remaining installed sensors, then the electrical inputs, and
finally the MFT itself.
The MFT information provides the model number of the unit, the serial number, firmware revision, and the
Flash information used to determine the date the firmware was installed.
Pressing Next after scrolling through all available information returns the user to the Measure mode screen.
Zero Mn/Max Damp More
Hold Sensr Rcal More

7
Rcal
Pressing the Rcal key enters the MFT into the Field Recalibration mode. This allows the unit’s sensors and
modules to be recalibrated in the field to maintain optimal accuracy. See section on Field Recalibration for
details.
SETTINGS
Press the Settings key to set the preferences on the MFT for lockout options, damp rates, auto shutoff time,
or clock edit. This will display the Settings menu. Note: Not all options will be active on every MFT
model. The Settings menu shows the current settings for the MFT and allows the user to make adjustments
through the use of the soft keys:
Settings Main Menu Screen
Pressing the Back soft key at this point will take you to the previous screen. Pressing the Back soft key when
in any of the Settings sub-menus will take you to the previous screen without making any changes.
Lockout Feature
To enable the lockout feature, make sure the selection cursor is pointed at Lockout. If not, scroll the
arrow Up using the soft keys. Choose the Lockout selection by pressing the Select soft key.
After selecting lockout, the MFT will enter the lockout settings menu. The current status is shown and three
choices are provided:
Lockout Main Screen
Disabled:All lockout features are disabled and all options on the menu are accessible for reconfiguration.
Enabled: Enables the lockout selections that are set in the View details screen.
View Details: This option takes the user to a screen listing all MFT parameters that can be protected by
lockout. These include All, Zero, Recalibration, Settings, Units, DOFs and Configurations. Individual
functions can be locked or, if preferred, the lockout can be set to deny unauthorized access to all parameters.
Settings
Current Settings:
Lockout: Disabled
Damp Rate 0.5 Sec
Off Timer Disabled
Clock Edit
U
p
Down Select Back
Settings
Lockout: Disabled
Disabled
Enabled
View Details
Up Down Select Back

8
To enable the lockout option, select Enabled by scrolling Down and press Select. The screen will switch
back to the original Settings screen that now shows the lockout status as Enabled.
Select Lockout again, scroll Down to View Details, and press Select. This screen allows the user to choose
which parameters to lockout. Use the Up and Down keys to scroll through the selections. Press Select to
choose the desired setting.
The screen will change and prompt you to enable or disable lockout for that function. Scroll Down to
enable and press Save.
Lockout Code
At this point the user will be prompted to enter a 3-digit lockout code. This code will be required to gain
access and change any parameter previously locked out. Use the Number Grid and soft keys to change the
lockout code value and the Select soft key to move to the next digit.
When you are satisfied with the choice for the lockout code, press Store. IMPORTANT: After the code is
entered, the user must cycle the power to activate the lockout mechanism.
BE SURE TO SAVE THIS CODE IN A SAFE PLACE IN THE EVENT YOU FORGET THE NUMBER. ACCESS TO
LOCKED-OUT FEATURES WILL BE DENIED WITHOUT THE PROPER CODE.
To select more than one option to lockout, simply complete your first selection, enter the Lockout code as
instructed above, and cycle through View Details until all the desired lockout options are enabled. Note: Be
sure to cycle power to activate the lockout feature.
To Disable Lockout
When you wish to edit a parameter protected by the lockout code, enter the three digit code when prompted
and press Save. You will now be able to edit the settings as described below. Entering an incorrect code will
display the message “Invalid Code.”
From the Settings menu Select Lockout and press Select. This screen allows the user to choose which
parameters to lockout. Use the Up and Down keys to scroll through the selections. Press Select to choose the
desired option. The screen will change and prompt you to enable or disable lockout for that function. Scroll
Down to Disabled and press Save.
Changing the Lockout Code
To change the lockout code, disable the lockout function for all the parameters selected, shut the unit off, and
follow the procedures outlined above.
Damp Rate
Damp is an exponential averaging function for measurements made over a selected time constant. This
function smooths the peaks and valleys of pulsating processes for a more stable display. To change the damp
rate on the unit, scroll Down to Damp and press Select. Scroll Up or Down to the damp rate desired. Press
Save to select the new value.

9
The damp rate can be set between 0.5 and 30 seconds. Once set, the damp rate feature can be activated or
deactivated from the Measure Mode by pressing the Damp soft key. Factory default for the damp rate is 0.5
seconds.
Off Timer
To conserve battery life, the MFT 4000 series allows the user to set the unit to shut off after a certain period
of keypad inactivity. To change the off timer on the unit, scroll Down to Off Timer and press Select. Scroll
Up or Down to the auto shut-off time desired. Press Save to select the new value.
The shutoff timer can be disabled or set to shut off after time periods of from 1 minute up to 2 hours.
NOTE: The Off Timer is disabled whenever the unit is powered by the optional AC Adapter (P/N A36742)
regardless of the set value.
Clock Edit
The Clock Edit option allows the user to change the date and time of the MFT’s internal clock. To select the
Clock Edit feature, make sure the pointer arrow is pointed to this selection. If not, scroll the arrow Down
using the soft keys. Choose Clock Edit by pressing the Select soft key.
Choose a clock or date option to adjust by scrolling Up or Down. Press Select to choose that option. You
will be prompted to make your changes by the Numeric Grid and underscore ( _ ). Use the Numeric Grid and
soft keys to change the value and the Select soft key to move to the next digit. When complete, press Done.
You will be asked if you wish to save the new data. Press Yes to accept the new value. Pressing No will take
you back to the Clock Edit without making any changes to the MFT clock.
To change the AM/PM option scroll Down to this option and press Select. Choose the AM or PM option by
scrolling up or down and press Save.
To go back to the Settings main menu press Back. To enter Measure Mode press the Back soft key again,
or simply press the Measure Mode key.
NOTE: When replacing the batteries, the date and time will remain active. Date & time information is
continuously powered by an internal, 10-year life back-up battery. This battery is not serviceable by the
user.

10
GENERAL OPERATION
Sensor Installation/Removal
To install a new sensor module into a sensor bay, make sure the spring-loaded sensor lock is facing toward
the rear of the MFT. Depress the sensor lock until the base of the sensor module passes into the sensor bay.
Push module into bay until it locks into place.
Once installed, the MFT will immediately read the data from the sensor and load it into the system. The
display will briefly show what sensor has been installed. The engineering units that were previously assigned
to that sensor module will automatically be displayed. Sensor modules may be installed in any sensor bay.
To remove a sensor module from a sensor bay, depress the spring-loaded sensor lock corresponding to the
module you wish to remove. The sensor lock needs to be depressed so that it clears the MFT housing. While
pressing down on the sensor lock, simultaneously pull upward on the module. A pen or small screwdriver
may be used to depress the sensor lock far enough to clear the housing.
Once a sensor module is removed from a bay, the display will clear that sensor’s information from the
display screen.
Note: Modules may be “hot swapped” or changed while the MFT is on or off. For intrinsically safe
versions, however, installation, removal or hot swapping must be done in a non-hazardous
environment only. See Hazardous Area Use section for more details.
Changing Units / Removing & Restoring Sensors on Display
Specific sensors can be turned on and off individually if they are not required. To turn off a specific sensor,
press the Shift key and select the corresponding Units Sensor key for the sensor you wish to remove from
the display. Repeatedly pressing the Units Sensor key will cycle through the available engineering units.
Before the unit cycle repeats, the sensor display will go blank. The sensor is now off. Press the Shift key
again to return to normal operation.
To reactivate a sensor that has been removed from the display, press the Shift key then press the
corresponding Units Sensor key. Continue to cycle through the engineering units by pressing the Units
Sensor key until the desired unit appears on the display. Press the Shift key to accept the engineering unit
and return to normal Measure Mode.
Note: Open sensor bays on the MFT should be protected with dummy modules (P/N A36741) to protect
the electrical connector and avoid contamination of or damage to the sensor bays. Dummy modules are
shipped as needed to fill MFT bays.
Sensor Module Locations
S1: Sensor Bay 1 (Left)
S2: Sensor Bay 2 (Center)
S3: Sensor Bay 3 (Right)

11
Sensor Module Engineering Units
Pressure Temperature
PSI º Fahrenheit
Inches of Water @ 20°Celsius º Celsius
Inches of Water @ 60º Fahrenheit º Rankin
Inches of Water @ 4º Celsius º Kelvin
KiloPascals Ohms
Kilograms/cm2milli-Volts
MilliBars
Bars
Centimeters of Water @ 20º Celsius
Inches of Mercury (Referenced @ 0º C)
Millimeters of Mercury (Referenced @ 0º C)
Installation & Removal of Batteries – standard MFTs
To install or remove the batteries, turn the MFT face down and pull down on the loose end of the Velcro
strap to separate it from the opposite side, then pull the strap through the lower metal strap guide. Use a
finger to push down and pull back on the battery cover latch to remove the cover. Be sure to follow the
polarity diagram shown on the bottom of the battery holders when installing the batteries. Make sure all
batteries are firmly secured. Replace cover, reinsert strap through metal strap guide, and re-secure the
Velcro.
Note: Replace all six (6) AA batteries at once with alkaline or NiMH cells. Do not mix alkaline or NiMH
batteries with each other or with other battery types. Batteries replacement is recommended when battery
icon shows one segment; however, the MFT will function briefly after the battery icon is empty.
Installation & Removal of Batteries – Intrinsically Safe MFTs
Intrinsically Safe rated MFTs have a battery compartment door fitted with two captive thumbscrews and
metallic bracket to mechanically secure the door to the MFT case. To install or remove batteries, follow the
above instruction and unscrew the two thumbscrews to remove door. After batteries maintenance is
complete, replace door and tighten thumbscrews re-secure.
Note: For Intrinsically Safe MFT models, replace batteries only with approved types. See the MFT
Intrinsic Safety Control Document in the Appendix for approved battery details.
Over Pressurization - Pressure Modules
If an MFT pressure sensor is over pressurized above its full scale pressure range, an “Overrange” warning
appears on the LCD above the engineering units of the affected sensor. If the applied pressure exceeds 20%
Rear of Intrinsically
Safe MFT shown
Thumbscrews / bracket
Battery door

12
of the sensor’s full scale range, the affected pressure measurement is replaced by an “Overrange” warning. If
this occurs, immediately release the pressure until the MFT displays a normal reading. Although pressures
are displayed up to 20% over full scale range, specified accuracy is guaranteed for full scale range only.
xGI (Gauge Isolated) and xAI (Absolute Isolated) Modules are capable of withstanding up to 2x the sensor
range without sustaining damage.
xDN (Differential Non-Isolated) Modules are capable of withstanding up to 2x the sensor range when
pressurized on the high side only. When pressure is applied to both the high and low side simultaneously, all
xDN sensors have a 150 PSI pressure limit.
x is a place holder for the sensor module accuracy designator. See information in the Appendix for
additional sensor module information.
Note: Subjecting pressure sensor modules to pressure limits beyond those listed above may damage the
sensors and void the warranty.
Media Compatibility - Pressure Sensors
Gauge (xGI) and Absolute (xAI) pressure sensor modules are compatible with fluid and gas medias that are
compatible with 316 stainless steel.
Differential (xDN) pressure sensors are for use with clean, dry, non-corrosive gases only.
APPLICATIONS
Gauge Pressure Calibration
The diagram below shows two typical set-ups for calibrating a gauge pressure unit under test. If the process
is a liquid, it is vital that the gauge under test be isolated and drained. If liquid enters a xDN module,
damage to the sensor can occur. To use a xDN sensor, connect the pressure source to the high pressure port
of the xDN sensor vent the low pressure port to atmosphere.
When calibrating a gauge pressure unit using a xGI sensor, the connection is the same with the exception that
the xGI sensor does not have an external vent to atmosphere.
In some cases the actual process may be used as the pressure source for calibration. If you choose to use the
process to perform the calibration, make sure the process is compatible with the sensor used, and that it
provides a stable pressure. If your process has a fluctuating or pulsating pressure, use of an external pressure

13
source is recommended to ensure the accuracy of your measurements and calibration.
Differential Pressure Calibration
Differential pressure gauges and transmitters can be calibrated using xDN or xGI sensor modules. The
following drawing depicts a typical calibration set-up. The units under test should be isolated from the
process and drained of liquids if necessary. The low pressure port of the DP unit under test is vented to
atmosphere. Do not connect the low pressure port of a xDN sensor to the low pressure port of the DP unit
under test. Such a dead end connection can cause errors due to the expansion or contraction of trapped gas as
a function of temperature change.
Meriam does not recommend using process pressure as the pressure source for DP pressure device
calibration. Errors in measurement and calibration can easily creep in if the pressure source is unstable. In
addition, xDN sensors have a maximum overpressure limit of 150 PSI when a three valve equalizing
manifold is used properly. Sensor damage can occur if more than 15 PSI is applied to the high or low side of
a xDN0020 or xDN0200 sensor through improper use of the equalizing manifold.

14
Additional DP Application Information
In addition to reading gauge pressures, the MFT can also be used to measure the pressure drop across a
device in a pressurized pipe. Examples include measuring the differential pressure across positive
displacement meters, filters, orifice plates or valves. Process compatibility and pressure ranges of the sensor
modules need to be considered for each application.
A three valve equalizing manifold or push-to-read equalizing valve should be used to avoid damaging xDN
sensors. Follow the specific operating procedure for each type of valve manifold.
3-Valve Manifold: Make sure all shut-off valves are closed. Connecting to the process. Slowly open the
equalizing valve. Slowly open the high pressure valve and then the low pressure valve. Close the equalizing
valve and take the measurement. Reverse the process to disconnect.
Push-to-read valve: Connect to the process. Open shut off valves. Push the push-to-read plunger to take the
reading.
Vacuum and Absolute Pressure Calibration
Vacuum calibrations can be performed with a xDN sensor module by venting the high pressure connection to
atmosphere and applying the vacuum to the low pressure connection. Atmospheric pressure is the reference
pressure for all vacuum measurements.
Absolute pressure calibrations use a xAI sensor module. These sensor modules have an internal absolute zero
reference. Simply connect the pressure (or vacuum) source to the single port on the module.
The following diagram shows the connection for both a vacuum and an absolute pressure measurement. If
the process maintains a stable pressure, it can be used as the pressure source in some calibrations. Process
compatibility and pressure ranges of the sensor modules need to be considered for each application.

15
ELECTRICAL CONNECTIONS – See Hazardous Area Use Section of this manual for
Intrinsically Safe guidelines / restrictions
MILLIAMP TRANSMITTER
The diagram below depicts the proper connection for measuring the current output from a transmitter. The
MFT is connected in series with the loop using standard banana jacks.
Important: Use the transmitter’s working terminals to measure mA, not the TEST terminals found on some
transmitters. Do not use digital communication terminals found on smart transmitters. These terminals will give
incorrect current reading.