mensor 9424 User manual

Operation Manual –PN 0040032001CS
Mensor Model 9424
Special Application Pressure Controller
Mensor Model 9424
Special Application Pressure Controller
Version 2.04.00 To 2.04.02
Mensor Model 9424 Special Application Pressure Controller
Manual PN 0040032001CS

Table of Contents
General Description.......................................................................................................... 1
Precautions ........................................................................................................................ 2
Unpacking and Initial Setup............................................................................................ 3
Pressure Connections...................................................................................................... 3
Electrical Connections.................................................................................................... 4
Operation........................................................................................................................... 4
Front Panel Operation.................................................................................................. 5
Keypad Entry Function............................................................................................... 5
Jog Functions.............................................................................................................. 6
Control Output Drivers............................................................................................... 6
Mode Selection and Display....................................................................................... 7
Unit Selection and Display ......................................................................................... 7
Control Stable Display................................................................................................ 7
Setup Button…………………………………………………………………………8
Setup - Jog (Small)………………….………………………………………………..8
Setup –Transducer Offset (Cal Zero)………………………………………………..8
Setup –Transducer Multiplier (Cal Span)…………………………………………...8
Pressure Setting Display……………………………………………………………..9
Pressure Reading Display……………………………………………………………9
Set Point Display......................................................................................................... 9
Info Display ................................................................................................................ 9
Remote Computer Controlled Operation................................................................... 9
Command Set.............................................................................................................. 9
Typical Operating Processes...................................................................................... 15
Calibration....................................................................................................................... 16
Tuning…………………………………………………………………………………. 17
Storage and Transportation........................................................................................... 19
Maintenance .................................................................................................................... 19
Specifications................................................................................................................... 20
Measurement Specifications ...................................................................................... 20
Control Specifications................................................................................................. 20
General Specifications................................................................................................ 21
Appendix.......................................................................................................................... 23

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 1
Mensor Model 9424
Special Application Pressure Controller
General Description:
The Mensor Model 9424 Special
Application Pressure Controller is a
single-channel pneumatic pressure
monitor/controller/calibrator. The range
of the instrument is preset by the
customer and can be up to 1500 psi
gauge or absolute pressure. The unit is
optimized for high-speed pressure tests
into volumes from near zero to 11 liters
or more. The instrument utilizes the
Mensor Series 6100 Digital Pressure Transducer for measurements. The transducer can
be mounted in a special design allowing rapid exchange of the transducer from the front
panel to facilitate external calibration. The standard Series 6100 transducers have an
accuracy of 0.010 % of span and a precision of 0.003 % of span with a 180-day
recommended calibration interval. (The Series 6180 can be offered in certain ranges with
higher accuracy and a 365-day recommended calibration interval.) The 9424 is housed in
an aluminum chassis having dimensions of 14.02” (35.61 cm) wide, 7.55” (19.2 cm)
high, and 12.42” (35.61 cm) deep. All porting extends from the rear of the chassis and
adds additional depth depending on fittings and connections to the unit. An optional rack
mount configuration is available for a standard 19” instrumentation rack, 4U height.
The front panel contains a color LCD monitor with a touch screen. Manual operation of
the 9424 is through the front panel. External pressure porting and electrical signal
connections are provided on the rear of the unit. Pressure ports include a supply input
port for clean dry inert media (air or nitrogen
preferred), a vacuum or exhaust port, and either a
single measure/control port or separate measure input
and control output ports. If separate measure and
control ports are installed, a pneumatic connection
manifold is provided (designated as the Remote
Pressure Sense Manifold, PN: 0017905001) to connect
the measuring port to the pressure output port near the
test volume. The advantage of this configuration is to
improve control speed with long hoses and large
volumes. Electrical connections consist of an RS-232
Serial Port for connection to a user computer and four
individual driver outputs to control external devices using 12 volt DC, 1 Amp drive.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 2
The instrument accepts
universal AC power (90 to
260 Volts AC, 50 or 60 Hz,
100 Watts). Power is
brought into the 9424 on a
standard IEC 320 power
entry module on the rear
panel. A power switch is
contained on the module
along with fuses and line
filters. Power is fused on
both the hot and neutral AC
lines entering the unit. No
switching or adjustments
are required.
Internally all components are powered by 5 Volt and 12 Volt DC supplies.
The Mensor 9424 communicates with a user-provided computer over a 3-wire RS-232
serial connection at a Baud of 57600, 8 data bits, 1 stop bit, and no parity.
Precautions:
1. The 9424 has a maximum supply pressure rating of 165 psi gauge for low-
pressure instruments and 1500 psi gauge for high-pressure instruments and a
recommended supply input of 110 % of the maximum installed transducer range.
The internal transducer has a burst rating of approximately 1.5x the full-scale
pressure.
2. The 9424 can operate in system configurations containing large pressure
storage tanks. Large vessels even at fairly low pressures can hold large amounts
of kinetic energy. Users should safely bleed all pressure stored in the tanks before
servicing, removing pressure hoses, or removing instruments. For units
configured below 400 psi, powering down the instrument should start the venting
process to relieve pressure from both internally and externally connected vessels,
but due to the size of the tanks and the desire to maintain a safe discharge rate;
this operation can take an extended period of time to achieve. Units configured
above 400 psi may require manual venting prior to powering down to discharge
pressure. If the exhaust port is connected to a vacuum device, a relief valve may
be required to protect the vacuum device from overpressure. If the exhaust port is
unconnected a muffler may be required to reduce noise on higher pressure
systems.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 3
3. In control mode pressure is discharged through the exhaust port on the rear
panel. In vent mode pressure is discharged through an internal port. On units
configured above 400 psi, the internal vent port will be fitted with a muffler.
4. The system uses normal power line AC voltages. The user should remove the
AC power cord from the mains
when servicing inside the 9424
chassis.
5. Any maintenance or
troubleshooting should be
performed by users knowledgeable
in pneumatic pressure
instrumentation and electronic
equipment.
Unpacking and Initial Setup:
The initial installation should include removing any packing material used in shipment
and inspecting that fittings and screws are snug, and that hoses and electrical cords are
not chaffed or cut. The Model 9424 should be installed on a level surface with adequate
airflow to keep the system within its 15 to 45 C optimum operating temperature range.
The system operates on line voltages between 90 and 260 VAC, 47 to 63 Hz. A source of
dry inert gas media is required for operation. This supply for full operation should be
approximately 110 percent of the range of the instrument, but should not exceed 165 psi
for low-pressure instruments (or 1500 psi gauge for high-pressure instruments.) Mensor
recommends that the gas supplied should be instrument quality. If compressed air is used
it should be a quality class of 1.2.1 or better as defined by ISO Standard 8573.1. This
limits dirt particles to less than 0.1 microns, a water pressure dew point of -40 C or lower
at 100 psig, and oil vapor of less than 0.008 ppm.
Pressure Connections:
The supply pressure should be connected to the rear panel lower left port labeled as
SUPPLY. The pressure should be approximately 110 % of range. For sub-atmospheric
pressure control, a vacuum pump is required and should be connected to the pressure port
labeled EXHAUST. If only pressures above barometric pressure are required, no vacuum
pump is needed and the EXHAUST port should be left open. If a pump is not used and
exhaust noise is excessive, a pressure muffler can be installed on the exhaust port.
Mensor can provide recommendations on a suitable muffler. Porting on the rear of the
9424 are female 7/16-20 SAE straight thread. Adapters are provided to convert to ¼”
tube fittings or optionally 6 mm metric fittings on the exhaust or supply ports.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 4
For units with individual measure and control ports,
connection to the user’s device under test (DUT)
should be made with the Remote Pressure Sense
Manifold provided and shown to the right. This
manifold connects the MEASURE INPUT port and
the CONTROL OUT port of the 9424 closer to the
actual test device. Mensor provides two 2-meter
hoses to connect the two ports on the 9424 to the
two ports on the Remote Pressure Sense Manifold.
The DUT output port on the manifold should
connect to the DUT or near the DUT. The Remote
Pressure Sense Manifold ports are 7/16-20 SAE
straight thread. An adapter is provided to convert to ¼” tube fitting or optionally 6 mm
metric fitting on the “To DUT” output.
On units with a single measure/control port, connection to the user’s device under test
should be made directly. Long hose lengths or small hose diameters serving large
volume loads may require a 9424 with separate measure and control ports and the use of
a Remote Pressure Sense Manifold. (Consult the factory if the unit has difficulty
controlling large volumes.)
Electrical Connections:
The communication port on the rear of the instrument is provided for connection to a
user's computer. A short 9-pin male to 9-pin female D-Sub cable is provided to connect
to a PC serial port. The length of this cable can be extended if desired by the user.
Mensor recommends that a shielded cable be used and conform to local EMI standards.
On the rear panel, four Control Signals are available to drive external loads/devices.
Each of the four drives is capable of driving 1 Amp loads at 12 volt DC. Wiring is done
through a removable terminal block labeled from left to right as OUT1, OUT2, OUT3,
and OUT4. Front panel touchscreen buttons and remote commands allow user control of
these drive lines.
Operation:
Generally, the system once configured requires power, clean dry pressure media, and
possibly a vacuum source for sub-atmospheric control and near-atmospheric control.
Start-up operation commences when power is applied. The internal normally open vent
valve(s) should immediately energize to seal the system to prepare for operation. The
processor and display should go through internal self-tests and display the operating
screen within approximately 45 seconds.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 5
Front Panel Operation:
The 9424 powers up into the default
operating screen in the default mode of
measure and with the control set point
equal to the first pressure measured.
The screen is subdivided into functional
sections. The top row identifies the
instrument type. On the far right is the
numeric keypad, below the keypad are
the control jog functions, and below the
jog functions are the toggle buttons for
the external control signals. On the far
left of the screen is a large window
displaying the control set point value
near the top and the current measured
pressure reading below the set point value. The measured pressure reading also acts as
the pressure stable indicator. The reading is green if the pressure is stable and yellow if
the pressure is driving to a new control point. Below this window are 6 buttons labeled
Meas Mode, Ctrl Mode, Vent Mode, Unit Chg, Setup Scrn, and Edit Setup. The first
three buttons change the mode of operation from measure to control to vent. The Unit
change button brings up 4 menus of pressure units that can be selected. Pressing one of
the unit buttons immediately changes the set point value and the reading value to the new
units of measure. On initial power-up, the setup/status window is normally displayed
below the 6 buttons. The window can be called up if the SETUP SCRN, or EDIT
SETUP button is pressed. This window displays the model, serial number, pressure
range, stable window(stable tolerance), jog values, and transducer zero and span.
Keypad Entry Function:
The keypad (light blue in color)
normally found on the right side of
the screen is used for multiple
numeric data entries. Normally at
power up and whenever the set
point window is pressed, the
keypad is used for entering a
control set point value. This is
designated at the top of the keypad
with the word “SETPT:”. As
numeric values are entered they are
displayed in the window next to
“SETPT:”. The ‘CE’ key can be
used to clear the last keystroke and the ‘X’ key deletes the entire entry. Once the correct
value is entered, the ‘=’ key is used to accept the value and display it in the actual

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 6
Pressure Setting window. If the ‘=’ key is pressed with no new value entered, no changes
will be made to the value and the last value will be retained.
The EDIT SETUP function also uses
the keypad to change instrument
values such as Jog values and Stable
window values. The top bar of the
keypad window will indicate the
function and allow the user to enter
the value. Pressing the EDIT
SETUP button will sequence through
all editable values. Values are saved
on exit.
The last keypad function (SETPT or
SETUP) remains in effect until
changed. This allows new set points
to be entered one after another
without pressing inside the set point
window every time.
Jog Functions:
Below the keypad box are the control pressure jog buttons. These 4 buttons are labeled
“+++” for large positive pressure change, “+” for small positive pressure change, “-“ for
small negative pressure change, and “---“ for large negative pressure change. If the
current set point was 100 mbar and the large jog value was10 and the small jog value was
1, pressing the “+++” button would change the control set point to 110 mbar, and the “-“
would change the 100 mbar to 99 mbar. If the units were changed to psi, the 10 mbar jog
value would be converted to psi and the large jog would change the set point to .145 psi
(10 mbar equivalent). If a new jog value exceeds the range of the unit, it is ignored.
Both the large jog and the small jog can be changed using the EDIT SETUP button.
Control Output Drivers:
Below the keypad and Jog function buttons,
the control output (OUT1, OUT2, OUT3,
and OUT4) buttons can be found. Each of
the buttons controls the state of an output
line on the rear of the instrument. The
buttons function as on and off signal
toggles. The 9424 powers up with all
outputs in the OFF state. Pressing the
appropriate button will energize the output
and toggle the state to ON. When ON, the
output provides 12 volts DC between the +
and –pins on the rear panel. The maximum

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 7
load is 1 Amp current (sink or source). Mensor can provide attachments that allow the
12-volt dc drive signals to switch larger AC power loads such as vacuum pumps,
compressors, and AC enunciators up to 20 amps.
Mode Selection and Display:
In the center of the screen near the left side are the mode selection buttons. Three modes
consisting of measure (MEAS), control (CTRL), and vent (VENT) are available. The
mode that is currently active is displayed in green letters just above and to the right of the
buttons. The MEAS mode shuts off all control functions and reads the pressure applied
at the measuring port on the rear of the instrument, displaying the reading in the current
units of measurement in the reading window. The CTRL mode controls the pressure on
the CONTROL OUT port based on the pressure measured on the MEASURE INPUT
port. Both ports need to be connected together using the remote sensor manifold
provided. The VENT mode shuts off all control functions, opens the vent valve, and
vents internal and external pressure to atmosphere. The pressure is continuously
monitored and displayed in the pressure reading window area.
Unit Selection and Display:
Just to the right of the three mode
selection buttons is the UNITS CHG
button. This button brings up the unit
selection screen just below the button.
There are four screens each showing 10
different units of measurement. To
change the current unit, find and press
the desired unit button. If the selection
is not available, press either the
PREVious or NEXT button to display
the next 10 selections. Once a unit is
selected, it will be displayed in the
green pressure setting/pressure reading
window at the bottom. Both the unit
name and the unit number will be
listed.
Control Stable Display:
The color of the pressure reading is used to indicate the pressure's stable status. It will
turn green if the pressure difference between the measured pressure and the set point
value is less than the tolerance specified by the STABLE WINDOW value. Outside this
+ and –tolerance, the pressure reading value will be yellow. The default tolerance is
0.01% of full scale. This tolerance may be changed over the serial communications port
using the “STABLEWINDOW=” command or read back with the

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 8
“STABLEWINDOW?” query. The stable window value can be modified from the front
panel by pressing the EDIT SETUP button until STABLE WINDOW is highlighted in
blue and the keypad shows STABLE WINDOW above the numeric keys.
Setup Button:
The SETUP button displays the user's changeable values and other instrument-specific
information. These values can only be changed when the EDIT SETUP button is
pressed and the value is highlighted in blue. At this point, changes can be made using
the numeric keypad. Once the enter key is pressed, the setup screen will re-appear.
Changes are stored in the instrument or transducer and are retained through power-down
cycles.
Setup - Jog (Big)
This function allows the large positive and negative jog values to be set. Acceptable
values must be positive and within the range of the instrument in the current displayed
units of measurement. The same absolute value is used for both the ‘+++’ button (added
to the current set point value) and the ‘---‘button (subtracted from the current set point
value). No check is made to determine if the large jog is bigger than the small jog. The
user can use the buttons as desired.
Setup - Jog (Small)
This function allows the small positive and negative jog values to be set. Acceptable
values must be positive and within the range of the instrument in the current displayed
units of measurement. The same absolute value is used for both the ‘+’ button (added to
the current set point value) and the ‘-‘ button (subtracted from the current set point
value). No check is made to determine if the large jog is bigger than the small jog. The
user can use the buttons as desired.
Setup –Transducer Offset (Cal Zero)
This entry allows the calibration offset (in the transducer units only) to be monitored and
changed. The zero offset is a fixed value that is added to each pressure reading. It is
normally zero to start with and can be changed to adjust the pressure reading. This field
is a display-only field and must be adjusted on the transducer by qualified calibration
technicians. (See CPT6100 manual for more information.)
Setup –Transducer Multiplier (Cal Span)
This entry displays the transducer calibration span factor. The span is a multiplier
(normally a non-dimensional value of 1.0000) that adjusts each reading. This field must

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 9
be adjusted by a qualified calibration technician using proper equipment. (See CPT6100
manual for more information.)
Pressure Setting Display:
The pressure setting window displays the current control set point in the current units of
measurement. Pressing anywhere within the window sets the keypad function to accept
new set point values.
Pressure Reading Display:
The reading display window shows the current pressure value in the current units of
measurement. It is always active.
Info Display:
The info window is used for displaying user information. The displays vary based on
modes and conditions encountered.
Remote Computer Controlled Operation
Functions available from the front panel are also available remotely using the command
set found below. Communications between the user’s external computer and the Model
9424 use standard RS-232 serial communications. The protocol is 19200 baud, 8 data
bits, 1 stop bit, and no parity. The 9424 will accept upper, lower, and mixed-case ASCII
commands. All commands should be terminated with a linefeed character or a carriage
return character.
Responses to queries will terminate with a carriage return and a line feed.
A complete command set can be found below.
Command Set:
The following command set applies to software version V1.00. All commands should
terminate with a line feed or a carriage return. Responses are terminated with a carriage
return followed by a line feed. Commands are accepted in uppercase, lowercase, or
mixed-case characters. Commands should not be concatenated together and must be
separated with a linefeed or carriage return. The user should accept query responses prior
to sending additional commands.
Command
Description
Example
rdg?
Returns the pressure reading of
the internal measurement
transducer in the current units
of measurement. Returns 8
Send: "RDG?" Return:
"123.456"

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 10
characters with decimal point.
setpt=
Commands the instrument to a
new set point in the current
units of measurement.
Command takes effect
immediately if in the control
mode or prepares the unit to
control at this point when
placed in the control mode.
Command will be ignored if it
is less than minimum range of
instrument or greater than
range of instrument.
Send:
“SETPT=23.400”
Returns:
setpt?
Returns the current set point in
the current units of
measurement. Returns 8
characters with decimal point.
Send: “Setpt?”
Returns:“ 23.400”
mode=
Sets the mode of operation to
measure (MEAS), control
(CTRL), vent (VENT)
Send: “MODE=ctrl”
Returns:
mode?
Returns the current mode of
operation measure (MEAS),
control (CTRL), vent (VENT)
Send: “Mode?”
Returns: “MEAS”
unit=
Sets the displayed units to any
of the built in units. (See
UNITS? Query to obtain a list
of those built in.) Instrument
will accept either the unit
number (1,2 3,4…) or the unit
name (PSI, inHG, mBar, kPa,
Bar, mmHG, ATM, inH2o)
Send: “UNIT=mbar”
Returns: “mbar, 15”
Send: “UNIT=15”
Returns: “mbar, 15”
unit?
Returns the current units of
measurement
Send: “Unit?”
Returns: “mBar, 15 ”
units?
Returns a list of available units
of measurement by both the
unit number and the unit name.
The actual multiplier from PSI
to the units is also provided.
Send: “Units?”
Returns: “1 psi
1.000000
2 inHg@0C 2.036020
…
id?
Returns the unit identification
of the 9424.
Send: “ID?”
Returns: “Mensor
Model 9424 Spec App
Controller”
sn?
Returns the serial number of
the 9424.
Send: “SN?”
Returns: “990354”
stable?
Returns the control stable flag,
an indication of control value
Send: “Stable?”
Returns: “HI”,

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 11
being within the stablewindow
setting. A returned value of HI
indicates that the pressure
reading is above the stable
window setting, A returned
value of LO indicates that the
pressure reading is below the
stable window setting , and a
returned value of OK indicates
that the pressure reading is
within the window.
“LO”,
Or “OK”
stablewindow=
Sets the allowed pressure
difference (control set point
and measured pressure reading)
to indicate a stable setting. The
setting is in the current units of
measurement.
Send:
“stablewindow=0.12”
Returns:
stablewindow?
Returns the allowable stable
error setting. This is the
allowed pressure difference
between the control set point
and the measured reading in the
current units of measure
Send: “Stablewindow?”
Returns: “0.12”
zero=
With the proper password,
allows the current zero offset
value to be changed on the
internal transducer. See CPW=
command to enter the
password. The value sent
should be in the current units of
displayed measurement.
To make a 760 mmHg
read 770 mmHg, send
“zero=10.000”
To make a 300 psi unit
read 295, send
“zero=-5.0”
zero?
Returns the current zero offset
value on the internal
transducer. It is an offset in the
current units of measurement
and the base transducer unit of
measurement. All changes
should be made in the
displayed units of
measurement.
Send: "zero?"
Returns: "5.0 mmHg"
span=
With the proper password,
allows the current span
multiplier value to be changed
on the internal transducer. See
CPW= command to enter the
password.
Send: “span= 1.0”
Returns:

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 12
span?
Returns the current span
multiplier value on the internal
transducer. The Span is
typically a number around 1.00
Send: “span?”
Returns: "1.000"
pass=
Allows commands and queries
to be passed directly to the
internal Mensor 6100
transducer. Commands can be
found in the Mensor Model
6100 Operation Manual
included in the appendix. Since
the passed commands can
change the calibration of the
transducer, they are password
protected like the zero and span
commands. See CPW=
command for details.
PASS=#1?
To read the pressure
reading directly from
the internal transducer.
lockpanel
Disables the front panel touch
screen to force only remote
communications and ignore
manual front panel operations.
Turning the power off and back
on resets the unit to allow
touch screen events or the
Unlockpanel command can be
sent.
Send: “LOCKPANEL”
Returns:
unlockpanel
Enables operation from the
front panel or over the serial
communication port.
Send:
“UNLOCKPANEL”
Return:
panelstate?
Returns the panel lock
condition.
Send: "Panelstate?"
Returns: "Panel Lock
ON"
Or "Panel Lock OFF"
version?
Returns the software version in
the instrument.
Send: "version?"
Returns: "V2.04.02"
echoon
Turns on command echo for
the remote serial
communications port. Can be
turned off with the EchoOFF
command. Unit defaults to
EchoOn at power up.
Send:“ECHOON”
Returns:
echooff
Turns off command echo for
remote serial communications
port. Can be turned on with the
EchoOn command or by
cycling the unit power.
Send: “ECHOOFF”
Returns:

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 13
cpw=
Calibration password required
to change the zero offset or
span multiplier on the internal
transducer. The calibration
password if accepted (correct)
will return “CPW”. A correct
password will allow the zero,
span and pass= commands to
be used within the next four
commands before it is disabled
and the password must be
entered again.
Send: “cpw=123456”
Returns:"CPW"
out1on
Turn on output 1
out1off
Turns off output 1
out2on
Turn on output 2
out2off
Turns off output 2
out3on
Turn on output 3
out3off
Turns off output 3
out4on
Turn on output 4
out4off
Turns off output 4
outon
Turns all outputs on
outoff
Turns all outputs off
jogbig=
Sets the jog value from a
typical value of 10 to a new
value. After entry, the value is
used any time the JOG+++ or
JOG--- keys are pressed. This
value is saved through power
cycles.
Send: “jogbig=20”
Returns:
jogsmall=
Sets the jog value from a
typical value of 1 to the new
value. After entry, the value is
used any time the JOG+ or
JOG- keys are pressed. This
value is saved through power
cycles.
Send: “jogsmall=2”
Returns:
setrate?
Returns the control rate.
Send: “setrate?”
Returns: "25.0000"
setrate=
Assigns the control rate.
Send: “setrate=25”
Returns:
rate?
Returns the current rate of
change in pressure in displayed
units/second.
Send: “rate?”
Returns: "12.3456"
rateon
Turns on rate control
Send: “rateon”
Returns:
rateoff
Turns off rate control
Send: “rateoff”

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 14
Returns:
ratestat?
Returns the current rate control
setting.
Send: “ratestat?”
Returns: "Rate control
is ON" or "Rate control
is OFF"
kp?
This is how much gain is given
to the rate position error
(Default value = .5). Too much
and it will overshoot or
oscillate around the setpoint.
Too little and it will be
sluggish at the rate setpoint.
Send: “kp?”
Returns: ".5000"
kp=
Assigns the position gain value.
Send: “kp=1”
Returns:
ki?
Integrator gain (default value =
80). This is how much gain is
given to the integrator
error.Globally applied without
regard to how much postion
error there is.
The control algorithm mainly
controls with the integrator
term, hence the higher gain, the
more rapid rate of correction.
Send: “ki?”
Returns: "80"
ki=
Assigns the integrator gain
value.
Send: “ki=100”
Returns:
itime?
This is the integrator time
constant (Default value = .01)
The amount of error transferred
to the integrator each cycle
If you make this value too big,
the unit will oscillate around
the rate setpoint
It can also cause oscillations at
the pressure setpoint.
if you make it too small, it wiil
not track the control rate
Send: “itime?”
Returns: ".0100"
itime=
Assigns the value for the
Integrator time constant.
Send: “itime=.0050”
Returns:
decaytime?
This is the number of seconds
before reaching the setpoint
that the control rate will start to
decay (Default Value= 4).
To speed up control make this
number smaller.
To reduce overshoot or
Send: “decaytime?”
Returns: "4.0000"

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 15
oscillations at the pressure
setpoint, make this number
larger.
decaytime=
Assigns the value for the Decay
Time.
Send: “decaytime=3”
Returns:
Added in versions 1.10
JogBig=
Sets the jog value from a
typical value of 10 to a new
value. After entry, the value is
used any time the JOG+++ or
JOG--- keys are pressed. This
value is saved through power
cycles.
Jogbig=20.000
JogSmall=
Sets the jog value from a
typical value of 1 to the new
value. After entry, the value is
used any time the JOG+ or
JOG- keys are pressed. This
value is saved through power
cycles.
Jogsmall=.001
Typical Operating Processes:
A typical operation would consist of setting up the supply, measure, and control hoses to
the appropriate ports. If power is not applied to the 9424, it should be powered up. The
unit will initialize into the measure mode with the initial control set point equal to the
first measured pressure reading. If pressure control is desired, the incoming supply
pressure should be adjusted to the recommended pressure in the Unpacking and Initial
Setup section, but not more than 165 psi gauge for low-pressure units or 1500 psi for
high-pressure units.
To control pressure, verify the control setting is within an acceptable value with respect
to any connected devices and then select the control mode button CTRL MODE. Once in
the control mode, new control points can be entered from the numeric keypad and
pressing the ‘=’ key. Also, the jog functions can be used to jump in uniform steps
through the useable pressure range. At the end of the process, the VENT mode can be
used to vent internal pressure. The unit should be left in the measure mode when not
being utilized or can be powered off if the unit is not needed for an extended period of
time to reduce energy consumption.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 16
Calibration:
Calibration of the pressure equipment should be done periodically.
Mensor CPT6100 Digital Pressure Transducers have a
recommended calibration interval of 180 days. Units equipped
with Mensor 6180 Digital Pressure Transducers have a
recommended calibration interval of 365 days. This interval can
be extended or shortened depending on the requirements of the
intended application and historical calibration data.
The transducer in the Model 9424 can be removed from the unit for calibration. If the
transducer is removed from the unit, an optional power supply, cable, and software are
required to perform the remote calibration. (Contact
Mensor if this option is preferred.) To remove the
transducer when removable options are chosen, turn the
power off and allow time for the unit to vent any
pressure externally and internally. Loosen the two
screws on the right side of the front panel to open the
panel door. The transducer should be in the front on the
right side of the chassis. Two screws (highlighted in red
in the photo to the right) near the bottom of the
transducer toward the back should be removed. The
transducer should be pulled out sufficiently to remove
the 9-pin d-sub connector on the top. A CPT 6100
Operation Manual describing the calibration process is
included in the appendix. The transducer is set for an
address of ‘A’ and a protocol of 19200 baud, 8 data bits,
1 stop bit, and no parity. The transducer is set up for
standard RS-232 communications. Utilize instructions
and connection recommendations found in the CPT 6100
Manual section 4.
To calibrate the Mensor 6100 transducer(s) when mounted inside the Model 9424
chassis, an external pressure standard needs to be connected to the MEASURE Port on
the rear of the instrument and the 9424 needs to be powered up and left in the
MEASURE mode of operation. Calibration checks can be performed with a precision
pressure standard. See CPT 6100 Operation Manual in the appendix for typical
calibration setup and instructions.
Adjustments to the calibration are done by changing the zero offsets and span multiplier
on the transducer. This can be done over the communication bus or through the front
panel.

Mensor Model 9424 Special Application Pressure Controller 0040032001CS May 25,2023 17
Tuning the Model 9424 Pressure Controller
When tuning the Model 9424, there are several variables to consider such as the DUT
volume, pressure range and control rate from one setpoint to the next. To operate the
Model 9424 efficiently, users must tune the machine to match their performance
requirements. Ideally, when the Model 9424 has been tuned correctly, there will be little
or no overshoot when controlling to a given setpoint and the pressure will be stable once
it reaches the desired setpoint.
No Overshoot when controlling and stable at setpoint
Overshoot when controlling up and down to a setpoint
Unstable at setpoint