Meriam M2 Series User manual

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 1 of 6
M2 – SERIES USER MANUAL
M202 PRECISION ABSOLUTE MANOMETER
Meriam Process Technologies’ M202 Precision Absolute
Manometer is a microprocessor based pressure sensing device
used to directly measure pressure relative to absolute zero.
Models are available to measure pressure ranges up to 900mm
Hg Abs and 2000mm Hg Abs. Pressure can be displayed in a
variety of engineering units. All units include a Tare function,
a Min/Max function, selectable damp rates and altitude
displayed in feet or meters. The M202 can also display
barometric pressure corrected to sea level.
ATEX rating:
0539 II 1 G
Ex ia IIC T4
(Tamb. -5ºC to +50ºC)
DE KO 06 ATEX 0615699
IP40
M202
Precision Absolute Manometer
M202
Precision Absolute Manometer
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 2 of 6
Table of Contents
User Interface ................................................................................
1. Keypad Functions ...............................................................
ON/OFF & BACK  KEY......................................................
MIN/MAX & UP  KEY .......................................................
TARE & DOWN  KEY........................................................
PRGM & ENTER  KEY....................................................... 4
BACKLIGHT KEY ................................................................. 4
2. Zeroing the Manometer....................................................... 5
. Program Mode .................................................................. 10
Units Select ............................................................................ 11
Displaying Altitude (US Standard Atmosphere 1962)............ 12
Display User Defined Altitude ............................................... 12
Pressure Corrected to Sea Level............................................. 15
Damp Rate Select................................................................... 17
User Info Select...................................................................... 18
Auto Shut-Off ........................................................................ 19
Lockout Select........................................................................ 20
Header Name.......................................................................... 21
Contrast Select ....................................................................... 22
Data Logging.......................................................................... 2
Leak Test................................................................................ 24
Re-Calibration ............................................................................. 25
RE-CALIBRATION – 1 Point EDIT and START ................. 27
RE-CALIBRATION – 5 Point EDIT ..................................... 28
RE-CALIBRATION – 5 Point START.................................. 29
RE-CALIBRATION – Restore Factory Defaults ................... 0
Specifications .............................................................................. 1
Certification/Safety/Warnings .....................................................
Changing the Batteries................................................................. 4
Contact Information..................................................................... 6

M2 Series Instruction Manual 9R68-A
Mar, 2008
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User Interface
1. Keypad Functions
ON/OFF & BACK 

 KEY
Turns the manometer on and enters the unit into the Measure
Mode. Pressing the key while in the Measure Mode turns the unit
off. It also serves as a backspace key when editing in the rogram
Mode. The  key takes the user out of a programmable register
without changing the previous setting. Pressing this key repeatedly
will return the user to the Measure Mode and then shut off the
manometer.
MIN/MAX & U 

 KEY
In the Measure Mode activates the Min/Max function of the
manometer. When activated the minimum value is displayed on the
upper left of the display and the maximum value on the upper right.
This key also deactivates and resets this function. The  key is
used to scroll through the programmable registers when the unit is
in the rogram Mode. Once a programmable register is selected
the  key can be used to edit that register.
TARE & DOWN 

 KEY
In the Measure Mode toggles on/off the Tare function. The Tare
function is designed to set the display value to “0”. With Tare
activated, the letter “T” appears in the lower left of the display.
The  key is used to scroll through programmable registers with
the unit in the rogram Mode. Once a programmable register is
selected the  key can be used to edit that register.
Tare

M2 Series Instruction Manual 9R68-A
Mar, 2008
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RGM & ENTER 

 KEY
Puts the manometer into the rogram Mode from the Measure
Mode. When in the rogram Mode, pressing this key selects the
programmable register to be edited (with prompt for password if
Lockout is set). After the register has been edited, pressing the
PRGM key enters the new setting into the manometer’s non-
volatile memory. This key also acts as a forward space  key
when editing user input such as the header name and user units.
BACKLIGHT KEY
The BACKLIGHT key, represented by the standard light bulb
symbol, toggles the display backlight between green and off.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 5 of 6
2. Zeroing the Manometer
The M202 Precision Smart Manometer is a stable and precise
instrument. However, on occasion the M202 should have a new
zero taken. This is done to remove zero drift that can occur since
the manometer was last zeroed. The M202 can be zeroed only if
the new applied zero is within ± 1% FS of the original factory
calibration zero. This prevents accidental zeroing at atmospheric
pressure or other relatively high pressures. If outside this limit a
“ZERO RANGE ERROR” message appears and the manometer
will not zero.
The M202 provides three mechanisms for re-zeroing:
1. Referenced to Absolute Zero: This traditional and
preferred method takes a “snapshot” of the measured pressure
when a vacuum of less than 100 microns Absolute is applied
to the sensor.
2. Factory Zero: This method restores the calibration curve to
the original zero taken at the factory. Note that this feature is
intended for comparison purposes, and should not be used for
real pressure measurement, as any zero-drift will not be
compensated.
. User-Adjusted Zero: This method allows the user to enter
any pressure value when a known reference is applied (for
example, the local barometer). The manometer will compare
its actual measured value with the entered value, and calculate
a new zero reference based on the offset.
1. To zero the manometer using Referenced to Absolute
Zero, start with the unit turned OFF and use the following
keystroke sequence:
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FAX [phone] - TestEquipmentDepot.com

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 6 of 6
Keystroke Display
1. Press ON/OF button. The display briefly shows
the header name and full
scale range of the unit in the
last engineering units
selected. The manometer
then goes into the Measure
Mode where the applied
pressure and engineering
unit of measure are
displayed.
2. Connect the 55 to a
vacuum source capable
of a vacuum of 100
microns absolute
pressure or less.
. Pull a full vacuum. Display should read close to
zero. (See note on next
page)
4. Press MIN/MAX and
TARE keys at the same
time. (See figure 1
below.)
Top line of display reads
“ZEROING SOURCE:”
Bottom line of display reads
“REF TO ABS ZERO”
5. Press the PRGM key. Top line of display reads
“ZERO IN PROGRESS”
while bottom line counts
down from 9. Zeroing is
complete when unit returns
to Measure Mode.
Figure 1
Tare

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 7 of 6
2. To zero the manometer using Factory Zero, start with the
unit turn ON and in Measure Mode and use the following
keystroke sequence:
Keystroke Display
1. Press MIN/MAX and
TARE keys at the
same time. (See
figure 1 above.)
Top line of display reads
“ZEROING SOURCE:”
Bottom line of display
reads “REF TO ABS
ZERO”
2. Press  or  arrow
key until desired zero
function is shown on
the bottom line.
Bottom line of display
reads “FACTORY ZERO”
. Press the PRGM key. Zeroing is complete when
unit returns to Measure
Mode.
NOTE: The M202 can be zeroed only if the new applied zero
is within ± 1% FS of the original factory calibration zero. If
outside this limit a “ZERO RANGE ERROR” message
appears and the manometer will not zero. Contact the factory
for support in this case.
. To zero the manometer using User-Adjusted Zero, start
with the unit turn ON and in Measure Mode and use the
following keystroke sequence:

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 8 of 6
Keystroke Display
1. Apply a known,
accurate pressure
source. This may be
true atmospheric
pressure, with known
reference defined by a
local barometer.
2. Press MIN/MAX and
TARE keys at the
same time. (See
figure 1 above.)
Top line of display reads
“ZEROING SOURCE:”
Bottom line of display
reads “REF TO ABS
ZERO”
. Press  or  arrow
key until desired zero
function is shown on
the bottom line.
Bottom line of display
reads “USER ADJ.
ZERO”
4. Press the PRGM key. Top line of display shows
the current non-zero
compensated pressure
value. Bottom line of
display shows the same
value, along with the
engineering unit.
5. Press any of  or 
arrow key or the
PRGM key to begin
editing.
Top line of display
continuously updates.
Bottom line of display data
is frozen, and the first digit
is blinking.
Example: set current
pressure value to 29.5
In Hg @ 0º C.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 9 of 6
6. Press the  or 
arrow key to set the
first digit to 0.
Current: xxx.xx
0xx.xx INHG
Using the UP arrow
key the character
sequence is 0 - 9, (-)
negative, (.) decimal
point. The (-) sign is
used if your location
is below sea level.
7. When the digit is
correct press the
PRGM key.
Cursor flashes to the right
of “0”.
If an error is made use
the back space  key
to move the cursor
back to the incorrect
digit. Press the UP 
or DOWN  arrow
keys to display the
correct value.
8. Continue this process
until the display reads
as shown at right.
Current: xxx.xx
029.50 INHG
9. Press the PRGM key
to enter the final
digit.
Zeroing is complete when
unit returns to Measure
Mode.
Note that the User Adjusted Zero feature will not accept
entries in altitude units (FEET or METERS). When the current
engineering unit is FEET, the User Adjusted Zero function
will automatically prompt for an entry in Inches of Mercury @
0º C. When the current engineering unit is METERS, the User
Adjusted Zero function will automatically prompt for an entry
in Millimeters of Mercury @ 0º C.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 10 of 6
3. rogram Mode
The program mode is used to configure the manometer for
Measure Mode operation. After the RGM key is pressed in
Measure Mode, the top line of the display reads “PROGRAM
MODE”. The bottom line reads “UNITS SELECT”. Press the  or
 arrow keys to scroll through the Program Mode to the desired
register. The configurable registers found in the rogram Mode
are Units Select, Damp Rate Select, User Info Select, Contrast
Select, Sea Level Select, Data Logging, Leak Test and Exit.
Press the RGM key to select any of these configurable registers.
The manometer can be put into rogram Mode at any time during
Measure Mode operation by pressing the RGM key. If Lockout
is set, the correct code must be entered when prompted (see the
User Info / Lockout section of this manual for more information on
Lockout).

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 11 of 6
Units Select
The standard engineering units available on the M202 Precision
Absolute Manometer are:
Inches of Mercury at 0° C (in Hg @ 0° C)
Millimeters of Mercury at 0° C (mm Hg @ 0° C)
SI
k a
mbars
Bars
Torr
Feet (Altitude displays)
Meters (Altitude displays)
To change the engineering units the manometer should be “ON”
and in Measure Mode. Then follow these steps:
Keystroke Display
1. Press the PRGM key. Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
2. Press the PRGM key. Top line reads “UNITS
SELECT” and bottom line shows
current engineering units.
. Press the  or  arrow
key until desired engineer-
ing unit is displayed.
Engineering units on bottom line
of display change.
4. Press the PRGM key to
select the engineering unit.
Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
5. Press the  arrow key. Bottom line reads “EXIT”.
6. Press the PRGM key. Display returns to Measure Mode
in new engineering unit.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 12 of 6
Displaying Altitude (US Standard Atmosphere 1962)
The model M202 is capable of displaying altitude in feet or meters
based on U.S. Standard Atmosphere1962 tables. To set the M202
to read out referenced to this altitude standard use the following
steps:
Keystroke Display
1. Press the PRGM key. Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
2. Press the PRGM key. Top line reads “UNITS
SELECT” and bottom line shows
current engineering unit.
. Press the  or  arrow
key until “USER UNIT
SELECT” is displayed.
Top line reads “UNITS
SELECT”
Bottom line reads “FEET or
METERS”.
4. Press the PRGM key. Top line reads “ALTITUDE
SELECT”. Bottom line reads
“STANDARD”.
5. Press the PRGM key. Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
6. Press the  key. Manometer returns to Measure
Mode. Displays altitude
referenced to US Standard
Atmosphere 1962.
Display User Defined Altitude
User Defined Altitude is useful in determining elevation change
from a map elevation reference or from a survey trig marker
elevation. To set up the M202 to display altitude based on user
entered information, use the following steps:
Keystroke Display
1. Press the PRGM key. Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 1 of 6
2. Press the PRGM key. Top line reads “UNITS
SELECT” and bottom line shows
current engineering unit.
. Press the  or  arrow
key until “USER UNIT
SELECT” is displayed.
Top line reads “UNITS
SELECT”
Bottom line reads “FEET or
METERS”.
4. Press the PRGM key. Top line reads “ALTITUDE
SELECT”. Bottom line reads
“STANDARD”.
5. Press the  arrow key
once.
Top line reads “ALTITUDE
SELECT”. Bottom line reads
“REF. TO USER”.
6. Press the PRGM key. Top line reads “VALUE=:
00000000”. Bottom line reads
“CHANGE?: NO”.
7. If the value shown in
step 6 is the correct
altitude, press the RGM
key to accept and the 
key to return to Measure
Mode.
- OR -
If the value shown in step
6 is not the correct
altitude, press the  key
Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
Top line reads “VALUE=:
00000000”. Bottom line reads
“CHANGE?: YES”.
8. Press the PRGM key.
Example: set altitude to
685 feet above sea level.
Top line reads “USER MODE-
FEET”. Bottom line reads
“00000000”.
9. Press the  or  keys
to set the first digit to “6”.
Using the  key the
provides the character
sequence 0 - 9, ( - )
negative, and (.) decimal
point. The ( - ) sign is used
if your location is below
sea level.
Top line reads “USER MODE-
FEET”. Bottom line reads
“60000000”.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 14 of 6
10. When the digit is
correct press the PRGM
key.
If an error is made use the
back space  key to move
the cursor back to the
incorrect digit. Press the
 or  arrow keys to
display the correct value.
Cursor flashes to the right of the
“6”. Example: “60000000”.
11. Continue the process
until the display reads as
shown at right.
Top line reads “USER MODE-
FEET”. Bottom line reads
“685.0000”.
12. Press the PRGM key
to enter the final value.
Top line reads “PROGRAM
MODE”. Bottom line reads
“UNITS SELECT”.
1 . Press the  key to
return to Measure Mode.
Top line reads “altitude
referenced to 685”. Bottom line
reads “U 685 FEET”.
To set the unit to read in meters, select METERS from the UNITS
SELECT menu. Then follow the same steps as outlined above.
Because the local barometer varies with weather conditions, the
USER DEFINED ALTITUDE must be reentered each time the
M202 is to be used in this mode. To adjust the unit to the current
barometric pressure without changing the base altitude, select
“NO” in step 6 in the table above by pressing the PRGM key. The
M202 will display the current altitude referenced to prevailing
local barometric pressure. To maximize accuracy the local altitude
should be reset whenever better altitude information is available.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 15 of 6
ressure Corrected to Sea Level
Pressure reduction to Sea Level is required so that barometric
readings can be compared at different elevations. The correction to
sea level is done using a “hypsometric equation”. This equation
simulates a “fictitious column of air” which extends downward
from the instruments location to sea level. This fictitious column is
assumed to be similar to the actual air column over nearby lower
elevations. Some properties are related to observed conditions
while others must be assumed. Barometric pressures given by the
National Weather Service and used at airports are always corrected
to sea level.
To set the unit to display pressure corrected to sea level:
Keystroke Display
1. Determine the elevation of
the instrument above sea
level, in meters. 700 meters
will be used as an example.
2. From Measure Mode press
the PRGM key.
Top line reads “PROGRAM
MODE”. Bottom line reads
“UNITS SELECT”.
. Press the  key 4
times.
Top line reads “PROGRAM
MODE”. Bottom line reads
“SEA LEVEL SELECT”.
4. Press the PRGM key. Top line reads “SEA LEVEL
SELECT”. Bottom line reads
either “ENABLE” or
“DISABLED”.
5. Press the  or  key
to indicate the correction
to sea level status.
Bottom line toggles between
“ENABLE” and
“DISABLED”.
6. To turn on the correction,
set ENABLED on the 2
nd
line & press the PRGM key.
-OR-
To turn off the correction, set
DISABLED on the 2
nd
line
and skip ahead to step 12 .
Top line reads “VALUE=:
00000000”. Bottom line reads
“CHANGE?: NO”.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 16 of 6
7. To change the value press
the  key to toggle the
display to “YES”.
Top line reads “VALUE=:
00000000”. Bottom line reads
“CHANGE?: YES”.
8. Press the PRGM key. Top line reads “SEA LEVEL
METERS”. Bottom line reads
“00000000”.
9. Press the  or  arrow
keys to set the correct value
in the first digit.
Top line reads “SEA LEVEL
METERS”. Bottom line reads
“70000000”.
10. When the value is correct
press the PRGM key.
Cursor moves over to the next
digit.
11. Repeat steps 9 and 10
above until the correct
elevation is entered.
Top line reads “SEA LEVEL
METERS”. Bottom line reads
“700.0000”.
12. Press the PRGM key to
continue moving the cursor
to the right. When the last
digit is entered the unit will
leave the sea level select
mode and return to the
Program Mode.
Top line reads “PROGRAM
MODE”. Bottom line reads
“UNITS SELECT”.
1 . Press the  key. The
display will return to the
Measure Mode. When the
Correction to Sea Level is
ENABLED, the display will
have the letter “S” at the
beginning of the 2
nd
line.
Display reads;
“S 80 .1 TORR”
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FAX [phone] - TestEquipmentDepot.com

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 17 of 6
Damp Rate Select
Adjustable exponential type damping is available to steady the
display when measuring pulsating pressures. The M202 has a range
of damping rates; 0.1, 0.2, 0.5, 1, 2, 5, 10, or 25 seconds. Damping
is done by averaging new data from the pressure sensor against
previously collected data. The microprocessor collects data from
the sensor every 0.1 seconds. The display updates every 0.5
seconds, showing the current 0.1 second pressure reading. When set
at 25 seconds, the display updates every 0.5 seconds with the
average of the previous 25 seconds readings. Therefore, it takes up
to 25 seconds from the time pressure is applied until the manometer
displays the full scale applied pressure. Min/Max display updates
every 0.1 seconds.
To set the damp rate:
Keystroke Display
1. Enter Program Mode by
pressing the PRGM key.
Top line reads “PROGRAM
MODE”. Bottom line reads
“UNITS SELECT”.
2. Press the  key. Bottom line reads “DAMP
RATE SELECT”.
. Press the PRGM key. Top line reads “DAMP RATE
SELECT”. Bottom line shows
current value.
4. Press the  or  keys
until the desire damp rate is
displayed on the bottom line.
Bottom line shows damp rate
settings in seconds.
5. Press the PRGM key. Top line reads “PROGRAM
MODE”. Bottom line reads
“UNITS SELECT”.
6. Press the  key. Bottom line reads “EXIT”.
7. Press the PRGM key. Returns to Measure Mode.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 18 of 6
User Info Select
The User Info Select registers are designed to provide the user with
information on the hardware and software in the manometer. This
register provides read only information on the sensor’s serial
number, software version and date of manufacture. It also allows
the user to edit the Auto Shut-Off, Lockout and Start-Up Header
Name features.
To access the User Info Select registers, follow the steps below. To
configure a User Info Select register, follow the steps shown on the
following page.
Keystroke Display
1. From the Measure Mode
press the PRGM key.
Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
2. Press the  arrow key
twice
Bottom line changes to “USER
INFO SELECT”.
. Press the PRGM key. Bottom line shows serial
number.
4. Press the  arrow key. Software version number
shown.
5. Press the  arrow key. Manufacture date shown.
6. Press the  arrow key.
See instructions to set
AUTO SHUT-OFF later in
this manual.
Top line reads “AUTO SHUT
OFF” and bottom line reads
“ENTER TO SELECT”.
7. Press the  arrow key.
See instructions for using
LOCKOUT later in this
manual.
Top line reads “LOCKOUT
CODE” and bottom line reads
“ENTER TO SELECT”.
8. Press the  arrow key.
See instructions for editing
the Header later in this
manual.
Top line reads “HEADER
NAME” and bottom line reads
“MERIAM”. The cursor flashes
at bottom left.
9. Press the  arrow key to
go back to “USER INFO
SELECT” screen.
Top line reads “PROGRAM
MODE” and bottom line reads
“USER INFO SELECT”.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 19 of 6
Auto Shut-Off
Enabling the Auto Shut-Off feature allows the manometer to turn
itself off after a user selected period of keypad inactivity.
Selectable options include DISABLED, 10 Minutes (which is the
factory shipped default), 20 Minutes, 0 Minutes, 45 Minutes and
60 Minutes. Disabling this feature limits the manometer to being
turned off by using the ON/OFF key only.
To configure auto shut-off follow these steps:
Keystroke Display
1. Follow steps 1-6 in the
User Info Select table.
Top line reads “AUTO SHUT-
OFF” and bottom line reads
“ENTER TO SELECT”.
2. Press the PRGM key,
then the up or down
arrow keys until the
desired shut-off time is
shown.
Top line reads “AUTO SHUT-
OFF” and bottom line toggles to
“DISABLED”, “10”, “20”, “ 0”,
“45” and “60” minutes .
. Press the PRGM key. Desired Auto Shut-Off time is
selected, top line reads “AUTO
SHUT-OFF” and bottom line
reads “ENTER TO SELECT”.
4. Press the left arrow key
twice.
Returns to Measure Mode.
Note: The “Auto Shut-Off” timer is suspended during Data
Logging and Leak Test sessions to prevent accidental loss of
information. Auto Shut-Off is re-instated after completion of Data-
Logging or Leak Test sessions.

M2 Series Instruction Manual 9R68-A
Mar, 2008
page 20 of 6
Lockout Select
Enabling the Lockout feature prevents unauthorized users from
making changes to the configuration of the manometer. To enter
the Program Mode, the user must first enter the “password” (two-
digit Lockout Code) within approximately 40 seconds when
prompted. Failure to enter the correct two digit code within
approximately 40 seconds will return the unit to Measure Mode.
Any two-digit numeric code can be programmed. The factory
Lockout Code of 00 (which is the default as shipped from the
factory) disables the Lockout.
To set the Lockout Code follow these steps:
Keystroke Display
1. From the Measure
Mode press the PRGM
key. If the Lockout is set,
enter the correct
“password” when
prompted.
Top line reads “PROGRAM
MODE” and bottom line reads
“UNITS SELECT”.
2. Press the up arrow key
twice.
Bottom line reads “USER INFO
SELECT”.
. Press the right arrow
key then the up arrow key
four times.
Top line reads “LOCKOUT
CODE” and bottom line reads
“ENTER TO SELECT”.
4. Press the right arrow
key, then press the up or
down arrow keys to
change the first digit.
Press the right arrow key
to proceed.
Bottom line shows the old
Lockout Code. The cursor flashes
at the first position while the
value is changed, the cursor
moves to the right position once
the right arrow key is pressed.
5. Press the right arrow
key when the desired code
is set. Lockout is
activated.
Top line reads “LOCKOUT
CODE” and bottom line reads
“ENTER TO SELECT”.
6. Press the left arrow key
twice.
Returns to Measure Mode.