Pfeiffer Vacuum FullRange ITR 90 User manual

BG 5040 BEN
(
2015-12
)
A
PASSION FOR PERFECTION
ITR 90
FullRange® Bayard-Alpert Gauge
Operating Instructions

2BG 5040 BEN (2015-12) ITR 90
In all communications with Pfeiffer Vacuum, please specify the information on the
product nameplate. For convenient reference copy that information into the space
provided below.
This document applies to products with the following part numbers:
PT T12 146 300 (vacuum connection DN 25 ISO-KF)
PT T12 366 300 (vacuum connection DN 40 CF-R)
The part number (No.) can be taken from the product nameplate.
If not indicated otherwise in the legends, the illustrations in this docu-
ment correspond to the gauge with no. PT T12 146 300. They apply to
other gauges by analogy.
All ITR 90 versions are shipped with an instruction sheet (→[1]).
We reserve the right to make technical changes without prior notice.
All dimensions in mm.
The ITR 90 gauges have been designed for vacuum measurement of gases and
gas mixtures in a pressure range of 5×10-10 … 1000 mbar.
They must not be used for measuring flammable or combustible gases in mixtures
containing oxidants (e.g. atmospheric oxygen) within the explosion range.
The gauges can be operated in connection with a Pfeiffer Vacuum controller or with
other control devices.
Over the whole measuring range, the gauge has a continuous characteristic curve
and its measuring signal is output as logarithm of the pressure.
The gauge functions with a Bayard-Alpert hot cathode ionization measurement
system (p < 2.0×10-2 mbar) and a Pirani measurement system (p > 5.5×10-3 mbar).
In the overlapping pressure range of 2.0×10-2 … 5.5×10-3 mbar, a mixed signal of
the two measurement systems is output. The hot cathode is switched on by the
Pirani measurement system only below the switching threshold of 2.4×10-2 mbar
(to prevent filament burn-out). It is switched off when the pressure exceeds
3.2×10-2 mbar.
Typ:
No:
F-No:
V W
Pfeiffer Vacuum, D-35614 Asslar
Product Identification
Validity
Intended Use
Functional Principle

BG 5040 BEN (2015-12) ITR90.oi 3
Contents
Product Identification 2
Validity 2
Intended Use 2
Functional Principle 2
1Safety 4
1.1 Symbols Used 4
1.2 Personnel Qualifications 4
1.3 General Safety Instructions 4
1.4 Liability and Warranty 4
2Technicale Data 5
3Installation 8
3.1 Vacuum Connection 8
3.1.1 Making the Flange Connection 9
3.1.2 Removing and Installing the Electronics Unit 9
3.1.3 Using the Optional Baffle 10
3.2 Electrical Connection 12
3.2.1 Use With Pfeiffer Vacuum Gauge Controllers 12
3.2.2 Use With Other Controllers 12
4Operation 15
4.1 Measuring Principle, Measuring Behavior 15
4.2 Operational Principle of the Gauge 16
4.3 Putting the Gauge Into Operation 16
4.4 Degas 17
4.6 RS232C Interface 17
4.6.1 Description of the Functions 17
4.6.1.1 Output String (Transmit) 17
4.6.1.2 Input String (Receive) 19
5Deinstallation 20
6Maintenance, Repair 21
6.1 Maintenance 21
6.1.1 Cleaning the Gauge 21
6.2 Adjusting the Gauge 21
6.2.1 Adjustment at Atmospheric Pressure 21
6.2.2 Zero Point Adjustment 22
6.3 What to Do in Case of Problems 23
6.4 Replacing the Sensor 24
7Options 25
8Spare Parts 25
9Storage 25
10 Returning the Product 26
11 Disposal 26
Appendix 27
A: Relationship Output Signal – Pressure 27
B: Gas Type Dependence 28
C: Literature 29
For cross-references within this document, the symbol (→XY) is used, for cross-
references to further documents, listed under literature, the symbol (→[Z]).

4BG 5040 BEN (2015-12) ITR 90
1 Safety
DANGER
Information on preventing any kind of physical injury.
WARNING
Information on preventing extensive equipment and environmental damage.
Caution
Information on correct handling or use. Disregard can lead to malfunctions or
minor equipment damage.
Notice
Skilled personnel
All work described in this document may only be carried out by persons who
have suitable technical training and the necessary experience or who have been
instructed by the end-user of the product.
•Adhere to the applicable regulations and take the necessary precautions for the
process media used.
Consider possible reactions between the materials (→5) and the process
media.
Consider possible reactions (e.g. explosion) of the process media due to the
heat generated by the product.
•Adhere to the applicable regulations and take the necessary precautions for all
work you are going to do and consider the safety instructions in this document.
•Before beginning to work, find out whether any vacuum components are con-
taminated. Adhere to the relevant regulations and take the necessary pre-
cautions when handling contaminated parts.
Communicate the safety instructions to other users.
Pfeiffer Vacuum assumes no liability and the warranty becomes null and void if the
end-user or third parties
•disregard the information in this document
•use the product in a non-conforming manner
•make any kind of changes (modifications, alterations etc.) to the product
•use the product with accessories not listed in the corresponding product
documentation.
The end-user assumes the responsibility in conjunction with the process media
used.
Gauge failures due to contamination or wear and tear as well as expendable parts
(e.g. filaments) are not covered by the warranty.
1.1 Symbols Used
Symbols for residual risks
1.2 Personnel Qualifications
1.3 General Safety
Instructions
1.4 Liability and Warranty

BG 5040 BEN (2015-12) ITR90.oi 5
2 Technical Data
Display range (air, O2, CO, N2,) 5×10-10 … 1000 mbar, continuous
Measuring range (air, O2, CO, N2,) 1×10-8 … 10-2 mbar, continuous
Accuracy 15% of reading
(after 5 min stabilization)
Repeatability 5% of reading
(after 5 min stabilization)
Gas type dependence →Appendix B
Switching on threshold
Switching off threshold
2.4×10-2 mbar
3.2×10-2 mbar
Emission current
p ≤7.2×10-6 mbar
7.2×10-6 mbar <p <3.2×10-2 mbar
5 mA
25 µA
Emission current switching
25 µA 5 mA
5 mA 25 µA
7.2×10-6 mbar
3.2×10-5 mbar
Degas emission current
(p <7.2×10-6 mbar)
≈16 mA (Pde
g
as ≈4 W)
Control input signal 0 V/+24 VDC, active high
(control via RS232 →17)
Duration max. 3 min, followed by automatic stop
In degas mode, ITR 90 gauges keep supplying measurement values, however their
tolerances may be higher than during normal operation.
Output signal (measuring signal) 0 … +10 V
Display range 0.774 V … +10 V
(5×10-10 mbar … 1000 mbar)
Relationship voltage-pressure logarithmic, 0.75 V/decade
(→Appendix A)
Error signal <0.3 V/0.5 V (→23)
Minimum load impedance 10 kΩ
DANGER
The gauge must only be connected to power supplies, instruments or
control devices that conform to the requirements of a grounded extra-
low voltage (PELV). The connection to the gauge has to be fused
(Pfeiffer Vacuum controller fulfill these requirements).
Operating voltage at the ITR 90 +24 VDC (20 … 28 VDC) 1)
ripple max. 2 V
pp
Power consumption
Standard
Degas
Emission start (<200 ms)
≤0.5 A
≤0.8 A
≤1.4 A
Power consumption ≤16 W
Fuse necessary 1.25 AT
1) Measured at sensor cable connector (consider the voltage drop as function of
the sensor cable length).
Measurement
Emission
Degas
Output signal
Power supply

6BG 5040 BEN (2015-12) ITR 90
Electrical connector D-Sub, 15-pin, male (→13)
Cable for ITR 90
Analog values only
Without degas function
Analog values
With degas function
Analog values
With degas function
And RS232C interface
4 conductors plus shielding
5 conductors plus shielding
7 conductors plus shielding
Max. cable length (supply voltage 24 V1))
Analog operation
RS232C operation
≤35 m, conductor cross-section 0.25 mm²
≤50 m, conductor cross-section 0.34 mm²
≤100 m, conductor cross-section 1.0 mm²
≤30 m
Gauge identification 42 kΩresistor between Pin 10 (sensor
cable) and GND
Data rate
Data format
Connections (sensor cable connector)
TxD (Transmit Data)
RxD (Receive Data)
GND
9600 Baud
binary
8 data bits
one stop bit
no parity bit
no handshake
Pin 13
Pin 14
Pin 5
Function and interface protocol of the RS232C interface →17
Materials exposed to vacuum
Housing, supports, screens
Feedthroughs
Insulator
Cathode
Cathode holder
Pirani element
stainless steel
NiFe, nickel plated
glass
iridium, yttrium oxide (Y2O3)
molybdenum
tungsten, copper
Internal volume
DN 25 ISO-KF
DN 40 CF-R
≤24 cm3
≤34 cm3
Max. Pressure 2 bar (absolute)
DN 25 ISO-KF
DN 40 CF-R
≈290 g
≈550 g
Admissible temperatures
Storage
Operation
Bakeout
-20 … 70 °C
0 … 50 °C
+150 °C (without electronics unit)
Relative humidity
(year's mean / during 60 days) ≤65 / 85% (no condensation)
Use indoors only
altitude up to 2000 m NN
Type of protection IP 30
Sensor cable
RS232C interface
Vacuum
Weight
Ambiance

BG 5040 BEN (2015-12) ITR90.oi 7
4-40UNC 2B
DN 25 ISO-KF
DN 40 CF-R
4-40UNC 2B
Dimensions [mm]

8BG 5040 BEN (2015-12) ITR 90
3 Installation
DANGER
DANGER: overpressure in the vacuum system >1 bar
Injury caused by released parts and harm caused by escaping process
gases can result if clamps are opened while the vacuum system is
pressurized.
Do not open any clamps while the vacuum system is pressurized. Use
the type of clamps which are suited to overpressure.
DANGER
The gauge must be electrically connected to the grounded vacuum
chamber. This connection must conform to the requirements of a pro-
tective connection according to EN 61010:
•CF connections fulfill this requirement
•For gauges with a KF vacuum connection, use a conductive
metallic clamping ring.
Caution
Caution: vacuum component
Dirt and damages impair the function of the vacuum component.
When handling vacuum components, take appropriate measures to
ensure cleanliness and prevent damages.
The gauge may be mounted in any orientation. To keep condensates
and particles from getting into the measuring chamber, preferably
choose a horizontal to upright position. See dimensional drawing for
space requirements (→7).
When installing the gauge, make sure that the area around the connec-
tor is accessible for the tools required for adjustment while the gauge is
mounted (→21).
When installing the gauge, allow for installing/deinstalling the connectors
and accommodation of cable loops.
•The gauge is supplied with a built-in grid. For potentially contaminating appli-
cations and to protect the electrodes against light and fast charged particles,
installation (→10) of the optional baffle is recommended (→25).
•The sensor can be baked at up to 150 °C. At temperatures exceeding 50 °C,
the electronics unit has to be removed (→9) or an extension (Option →25)
has to be installed.
3.1 Vacuum Connection

BG 5040 BEN (2015-12) ITR90.oi 9
It is recommended not to apply any vacuum grease.
The protective lid will be needed for maintenance.
•Allen key, size 2.5 mm
Unscrew the hexagon socket set screw (1) on the side of the electronics
unit (2).
2
1
3.1.1 Making the Flange
Connection
Procedure
3.1.2 Removing and Installing
the Electronics Unit
Required tool
Removing the electronics unit

10 BG 5040 BEN (2015-12) ITR 90
Remove the electronics unit without twisting it.
Removal of the electronics unit is completed.
Place the electronics unit on the sensor (3) (be careful to correctly align the
pins and notch (4)).
4
3
Slide the electronics unit in to the mechanical stop and lock it with the hexa-
gon socket set screw (1).
The electronics unit is now installed.
In severely contaminating processes and to protect measurement electrodes opti-
cally against light and fast charged particles, replacement of the built-in grid by the
optional baffle (→25) is recommended.
The optional baffle will be installed at the sensor opening of the deinstalled gauge
(Deinstallation →20).
Caution
Caution: dirt sensitive area
Touching the product or parts thereof with bare hands increases the
desorption rate.
Always wear clean, lint-free gloves and use clean tools when working
in this area.
•Baffle (→25)
•Pointed tweezers
•Pin (e.g. pencil)
•Screwdriver No 1
Installing the electronics unit
3.1.3 Using the Optional Baffle
Installing/deinstalling
the baffle
Required tools / material

BG 5040 BEN (2015-12) ITR90.oi 11
Carefully remove the grid with tweezers.
Carefully place the baffle onto the sensor opening.
Using a pin, press the baffle down in the center until it catches.
The baffle is now installed (Installation of the gauge →8).
Procedure

12 BG 5040 BEN (2015-12) ITR 90
Carefully remove the baffle with the screwdriver.
See Pfeiffer Vacuum sales literature and data sources for controllers and our range
of sensor cables on our internet home page (www.pfeiffer-vacuum.com).
Plug the sensor connector into the gauge and secure it with the locking
screws.
Connect the other end of the sensor cable to the Pfeiffer Vacuum controller
and secure it.
The gauge can now be operated with the Pfeiffer Vacuum controller.
The gauge can also be operated with other controllers.
The application and length of the sensor cable have to be considered when deter-
mining the number and cross sections of the conductors (→6).
Open the cable connector (D-Sub, 15-pin, female).
Prepare the cable and solder/crimp it to the connector as indicated in the
diagram of the gauge used:
Deinstallation
3.2 Electrical Connection
3.2.1 Use With Pfeiffer Vacuum
Gauge Controllers
Procedure
3.2.2 Use With Other
Controllers
Cable type
Procedure

BG 5040 BEN (2015-12) ITR90.oi 13
WARNING
The supply common (Pin 5) and the shielding (Pin 15) must be
connected at the supply unit with protective ground.
Incorrect connection, incorrect polarity or inadmissible supply voltages
can damage the gauge.
For cable lengths up to 5 m (0.34 mm2 conductor cross-section) the
output signal can be measured directly between the positive signal out-
put (Pin 2) and supply common GND (Pin 5) without loss of accuracy. At
greater cable lengths, differential measurement between signal output
(Pin 2) and signal common (Pin 12) is recommended.
Reassemble the cable connector.
On the other cable end, terminate the cable according to the requirements
of the gauge controller you are using.
Electrical connection
Pin 2 Signal output (measuring signal) 0 … +10 V
Pin 5 Supply common, GND
Pin 7 Degas on, active high +24 VDC
Pin 8 Supply +24 VDC
Pin 10 Gauge identification
Pin 12 Signal common, GND
Pin 13 RS232C, TxD
Pin 14 RS232C, RxD
Pin 15 Shielding, housing, GND
Pins 1, 3, 4, 6, 9 and 11 are not connected internally.
8
91
15
D-Sub, 15-pin
female,
soldering side
TxD
ITR 90
42kΩ
RxD
Measuring signal
Degas
+U
b
13
14
2
12
7
8
5
15
1.25AT
Identification
10
RS232C
24 V
+
–
+
–
Sensor cable connection
ITR 90

14 BG 5040 BEN (2015-12) ITR 90

Plug the sensor connector into the gauge
and secure it with the locking screws.
Connect the other end of the sensor cable to the connector of the instru-
ment or gauge controller you are using.
The gauge can now be operated via analog and RS232C interface.

BG 5040 BEN (2015-12) ITR90.oi 15
4 Operation
The ITR 90 vacuum gauge consist of two separate measuring systems (hot
cathode Bayard-Alpert (BA) and Pirani).
The BA measuring system uses an electrode system according to Bayard-Alpert
which is designed for a low x-ray limit.
The measuring principle of this measuring system is based on gas ionization.
Electrons emitted by the hot cathode (F) ionize a number of molecules proportional
to the pressure in the measuring chamber. The ion collector (IC) collects the thus
generated ion current I+and feeds it to the electrometer amplifier of the
measurement instrument. The ion current is dependent upon the emission current
Ie, the gas type, and the gas pressure p according to the following relationship:
I+= Ie× p × C
Factor C represents the sensitivity of the gauge head. It is generally specified for
N2.
The lower measurement limit is 5×10-10 mbar (gauge metal sealed).
To usefully cover the whole range of 5×10-10 mbar … 10-2 mbar, a low emission
current is used in the high pressure range (fine vacuum) and a high emission cur-
rent is used in the low pressure range (high vacuum). The switching of the emis-
sion current takes place at decreasing pressure at approx. 7.2×10-6 mbar, at in-
creasing pressure at approx. 3.2×10-5 mbar. At the switching threshold, the ITR 90
can temporarily (<2 s) deviate from the specified accuracy.
Diagram of the BA measuring system
F hot cathode (filament)
IC ion collector
EC anode (electron collector)
IC
200V40V
+– +–
(Degas 250V)
ECF
F
EC
IC
Within certain limits, the thermal conductibility of gases is pressure dependent. This
physical phenomenon is used for pressure measurement in the thermal conduc-
tance vacuum meter according to Pirani. A self-adjusting bridge is used as meas-
uring circuit (→schematic). A thin tungsten wire forms the sensor element. Wire
resistance and thus temperature are kept constant through a suitable control cir-
cuit. The electric power supplied to the wire is a measure for the thermal conduc-
tance and thus the gas pressure. The basic principle of the self-adjusting bridge
circuit is shown in the following schematic.
4.1 Measuring Principle,
Measuring Behavior
Bayard-Alpert
Pirani

16 BG 5040 BEN (2015-12) ITR 90
The bridge voltage UBis a measure for the gas pressure and is further processed
electronically (linearization, conversion).
The ITR 90 gauge s continuously cover the measuring range
5×10-10 mbar … 1000 mbar.
•The Pirani constantly monitors the pressure.
•The hot cathode (controlled by the Pirani) is activated only at pressures
<2.4×10-2 mbar.
If the measured pressure is higher than the switching threshold, the hot cathode is
switched off and the Pirani measurement value is output.
If the Pirani measurement drops below the switching threshold (p = 2.4×10-2 mbar),
the hot cathode is switched on. After heating up, the measured value of the hot
cathode is fed to the output. In the overlapping range of 5.5×10-3 … 2.0×10-2 mbar,
the output signal is generated from both measurements.
Pressure rising over the switching threshold (p = 3.2×10-2 mbar) causes the hot
cathode to be switched off. The Pirani measurement value is output.
The output signal is gas type dependent. The characteristic curves are accurate for
dry air, N2and O2. They can be mathematically converted for other gases
(→Appendix B).
The measuring currents of the Bayard-Alpert and Pirani sensor are converted into
a frequency. A micro-controller converts this frequency into a digital value repre-
senting the measured total pressure. After further processing this value is available
as analog measurement signal (0 … +10 V) at the output (sensor cable connector
Pin 2 and Pin 12). The maximum output signal is internally limited to +10 V (
≙
atmosphere). The measured value can be read as digital value through the
RS232C interface (Pins 13, 14, 15) (→17). The default setting of the displayed
pressure unit is mbar. It can be modified via the RS232C interface (→17).
In addition to converting the output signal, the micro controller's functions include
monitoring of the emission, calculation of the total pressure based on the meas-
urements of the two sensors, and communication via RS232C interface.
When the operating voltage is supplied (→Technical Data), the output signal is
available between Pin 2 (+) and Pin 12 (–) of the sensor cable connector
(Relationship output signal – pressure →Appendix A).
Allow for a stabilizing time of approx. 10 min. Once the gauge has been switched
on, permanently leave it on irrespective of the pressure.
Communication via the digital interface is described in a separate section.
Schematic
Measuring range
Gas type dependence
4.2 Operational Principle of
the Gauge
4.3 Putting the Gauge Into
Operation

BG 5040 BEN (2015-12) ITR90.oi 17
Gauge failures due to contamination or wear and tear as well as ex-
pendable parts (e.g. filaments) are not covered by the warranty.
Deposits on the electrode system of the BA gauge can lead to unstable measure-
ment readings.
The degas process allows in-situ cleaning of the electrode system by heating the
electron collector grid to approx. 700 °C by electron bombardment.
Depending on the application, this function can be activated by the system control
via a digital interface. The ITR 90 automatically terminates the degas process after
3 minutes, if it has not been stopped before.
The degas process should be run at pressures below 7.2×10-6 mbar
(emission current 5 mA).
For a repeated degas process, the control signal first has to change from ON
(+24 V) to OFF (0 V), to then start degas again with a new ON (+24 V) command. It
is recommended that the degas signal be set to OFF again by the system control
after 3 minutes of degassing, to achieve an unambiguous operating status.
The built-in RS232C interface allows transmission of digital measurement data and
instrument conditions as well as the setting of instrument parameters.
The interface works in duplex mode. A nine byte string is sent continuously without
a request approx. every 20 ms.
Commands are transmitted to the gauge in a five byte input (receive) string.
•Data rate 9600 Baud set value, no handshake
•Byte 8 data bits
1 stop bit
•TxD Pin 13
•RxD Pin 14
•GND Pin 5
(Sensor cable connector)
The complete output string (frame) is nine bytes (byte 0 … 8). The data string is
seven bytes (byte 1 … 7).
Byte No Function Value Comment
0 Length of data string 7 (Set value)
1 Page number 5 (For ITR 90)
2 Status →Status byte
3 Error →Error byte
4 Measurement high byte 0 … 255 →Calculation of pressure value
5 Measurement low byte 0 … 255 →Calculation of pressure value
6 Software version 0 … 255 →Software version
7 Sensor type 10 (For ITR 90)
8 Check sum 0 … 255 →Synchronization
4.4 Degas
Contamination
4.5 RS232C Interface
4.5.1 Description of the
Functions
Operational parameters
Electrical connections
4.5.1.1 Output String (Transmit)
Format of the output string

18 BG 5040 BEN (2015-12) ITR 90
Synchronization of the master is achieved by testing three bytes:
Byte No Function Value Comment
0 Length of data string 7 Set value
1 Page number 5 (For ITR 90)
8 Check sum of bytes No 1 … 7 0 … 255 Low byte of check
sum 1)
1) High order bytes are ignored in the check sum.
Bit 1 Bit 0 Definition
0 0 Emission off
0 1
Emission 25 μA
1 0 Emission 5 mA
1 1 Degas
Bit 2 Definition
0 1000 mbar adjustment off
1 1000 mbar adjustment on
Bit 3 Definition
0 ⇔1 Toggle bit, changes with every
string received correctly
Bit 5 Bit 4 Definition
0 0 Current pressure unit mbar
0 1 Current pressure unit Torr
1 0 Current pressure unit Pa
Bit 7 Bit 6 Definition
x x Not used
Bit 3 Bit 2 Bit 1 Bit 0 Definition
x x x x Not used
Bit 7 Bit 6 Bit 5 Bit 4 Definition
0 1 0 1 Pirani adjusted poorly
1 0 0 0 BA error
1 0 0 1 Pirani error
The software version of the gauge can be calculated from the value of byte 6 of the
transmitted string according to the following rule:
Version No = ValueByte 6 / 20
(Example: According to the above formula, ValueByte 6 of 32 means software ver-
sion 1.6)
The pressure can be calculated from bytes 4 and 5 of the transmitted string. De-
pending on the currently selected pressure unit (→byte 2, bits 4 and 5), the ap-
propriate rule must be applied.
As result, the pressure value results in the usual decimal format.
pmbar = 10((high byte × 256 + low byte) / 4000 - 12.5)
pTorr = 10((high byte × 256 + low byte) / 4000 - 12.625)
pPa = 10((high byte × 256 + low byte) / 4000 - 10.5)
Synchronization
Status byte
Error byte
Software version
Calculation of the pressure
value

BG 5040 BEN (2015-12) ITR90.oi 19
The example is based on the following output string:
Byte No 0 1 2 3 4 5 6 7 8
Value 7 5 0 0 242 48 20 10 69
The instrument or controller (receiver) interprets this string as follows:
Byte No Function Value Comment
0 Length of data
string
7 (Set value)
1 Page number 5 ITR 90
2 Status 0
Emission = off
Pressure unit = mbar
3 Error 0
No error
4
5
Measurement
High byte
Low byte
242
48
Calculation of the pressure:
p = 10((242 × 256 + 48) / 4000 - 12.5) = 1000 mbar
6 Software version 20
Software version = 20 / 20 = 1.0
7 Sensor type 10 ITR 90
8 Check sum 69
5 + 0 + 0 + 242 + 48 + 20 + 10 =
325dec ≙
01 45hex
High order byte is ignored 
Check sum = 45hex ≙ 69dec
For transmission of the commands to the gauge, a string (frame) of five bytes is
sent (without <CR>). Byte 1 to byte 3 form the data string.
Byte no Function Value Comment
0 Length of data string 3 (Set value)
1 Data →admissible input strings
2 Data →admissible input strings
3 Data →admissible input strings
4 Check sum
(from bytes No 1 … 3) 0 … 255
(low byte of sum) 1)
1) High order bytes are ignored in the check sum.
For commands to the gauge, six defined strings are used:
Byte No
Command 0 1 2 3 4
2)
Set the unit mbar in the display 3 16 62 0 78
Set the unit Torr in the display 3 16 62 1 79
Set the unit Pa in the display 3 16 62 2 80
Power-failure-safe storage of current unit 3 32 62 62 156
Switch degas on
(switches itself off after 3 minutes)
3 16 93 148 1
Switch degas off before 3 minutes 3 16 93 105 214
2) Only low order byte of sum (high order byte is ignored).
Example
4.5.1.2 Input String (Receive)
Format of the input string
Admissible input strings

20 BG 5040 BEN (2015-12) ITR 90
5 Deinstallation
DANGER
DANGER: contaminated parts
Contaminated parts can be detrimental to health and environment.
Before beginning to work, find out whether any parts are contami-
nated. Adhere to the relevant regulations and take the necessary pre-
cautions when handling contaminated parts.
Caution
Caution: vacuum component
Dirt and damages impair the function of the vacuum component.
When handling vacuum components, take appropriate measures to
ensure cleanliness and prevent damages.
Vent the vacuum system.
Before taking the gauge out of operation, make sure that this has
no adverse effect on the vacuum system.
Depending on the programming of the superset controller, faults
may occur or error messages may be triggered.
Follow the appropriate shut-down and starting procedures.
Take gauge out of operation.
Disconnect all cables from the gauge.
Remove gauge from the vacuum system and replace the protective lid.
Procedure