LEYBOLD THERMOVAC TTR 91 N User manual

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THERMOVAC Transmitter
TTR 91 N, TTR 91 N S, TTR 96 N S and TTR 96 N SC
Operating Manual 300544652_002_C1
Part Numbers:
230035V02
230036V02
230037V02
230038V02
230040V02
230043V02
230045V02
230047V02

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Contents
Safety Information 3
Symbols used 3
Personnel Qualifications 3
General safety information 3
Liability and Warranty 5
Unpacking 6
Description 7
Technical Data 8
Dimensions 9
Accessories and replacement part numbers 10
Transmitter Installation (Mechanical) 11
Conforming utilization 11
Non-conforming utilization 11
Process compatibility 11
Vacuum connections 12
Pressure range 12
Transmitter Installation (Electrical) 13
Input/Output Wiring 14
Setpoint relays 15
Operations 16
Pressure output 16
Analog output 17
Sensor gas dependence 18
Functions 19
LED-ring/LED status indicator 19
Vacuum-zero/full-scale adjustment and setpoint adjustment 20
User switch adjustments 21
FAQ (Frequently Asked Questions) 25
Trouble shooting 27
Declaration of Contamination 28
Declaration of Conformity 30
Notes 31
Sales and Service 32

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Safety Information
Symbols used
The first two symbols identify other information in this manual that is essential or useful in achieving optimal
performance from the transmitter. The last symbol below is used throughout this manual to further define the safety
concerns associated with the product.
Calls attention to important procedures, practices or conditions.
Personnel Qualifications
General safety information
The safety instructions should always be followed during installation and operation of the transmitter.
Pass safety information to all users.
Adhere to the applicable regulations and take the necessary precautions for the process media used.
Consider possible reactions between the materials 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 contaminated. Adhere to the
relevant regulations and take the necessary precautions when handling contaminated parts.
Safety Precautions:
Failure to read message could result in damage to the equipment.
Refer to manual. Failure to read message could result in personal injury or serious damage to the equipment or
both.
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.
Explosive Environments. Do not use the transmitter in presence of flammable gases or other
explosive environments.
Corrosive Environments. The transmitter is not intended for use in corrosive environments. Refer
to Transmitter installation chapter 3 of this manual. If you need further support please contact
Leybold.
Critical
Attention
Critical
!
!
Caution
!
Skilled personnel

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Service and Repair. Do not substitute parts or modify instrument. Do not install substituted parts or
perform any unauthorized modification to the instrument. Return the instrument to an Leybold
Calibration and Service Center for service and repair to ensure all of the safety features are
maintained.
DANGER: contaminated parts
Contaminated parts can be detrimental to health and environment. Before beginning to work, find
out whether any parts are contaminated. Adhere to the relevant regulations and take the necessary
precautions when handling contaminated parts.
DANGER: Overpressure in the vacuum system
KF flange connections with elastomer seals (e.g. O-rings) cannot withstand pressures <2,5bar.
Process media can thus leak and possibly damage your health.
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.
CE marking The transmitter complies with European standards for CE marking. Refer to
Declaration of Conformity chapter 10 of this manual.
Fuse. The transmitter power supply input has an internal thermal fuse. The fuse is self-recoverable
and should not be changed.
Electrical connections. The transmitter must be properly electrically connected in order to perform
according to the specifications.
Output pins are not protected against wrong electrical connections. Wrong electrical connections
can cause permanent damage to the transmitter or interference to measuring performance.
Refer to electrical connections description in chapter 4 of this manual.
Caution: dirt sensitive area
Touching the product or parts thereof with one's bare hands increases the desorption rate.
Always wear clean, lint-free gloves and use clean tools when working in this area.
Critical
!
!
!
Caution
!
Caution
!
Critical
Attention
!
!
Attention
!
Caution
!
Critical
!

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Liability and Warranty
Leybold 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 interventions (modifications, alterations etc.) on the product
use the product with accessories not listed in the product documentation
The end-user assumes the responsibility in conjunction with the process media used. Transmitter failures due to contamination
are not covered by the warranty.

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Unpacking
Before unpacking your transmitter, check all surfaces of the packing material for shipping damage. Inspect for
visible damage. If found, notify the carrier immediately.
Please be sure that your transmitter package contains these items:
1 pcs. TTR 91 N or TTR 96 N THERMOVAC Transmitter
1 pcs. English short form manual (P/N: 300544666_002)
1 pcs. German short form manual (P/N: 300544666_001)
1 pcs. Product Inspection and Test Report
1 pcs. Pin for adjusting settings via button
If any items are missing, please contact Leybold.

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Description
The TTR 91 N and TTR 96 N THERMOVAC series vacuum transmitters offer a wide measuring range from 5×10-5
to 1000 mbar and are based on the measurement of thermal conductivity in a small cavity on a MEMS Pirani silicon
chip sensor.
The TTR 91 N and TTR 96 N THERMOVAC transmitters can be used in a variety of applications as standalone
units or with Graphix controllers (P/N: 230680V01, 230681V01, 230682V01) and the Display controllers (P/N:
230001, 230024, 230025). All THERMOVAC transmitters are backward compatible with Graphix, Display and
Center controllers.
Each transmitter is individually tested throughout the measuring range before leaving the factory. A test report is
included in the package. In addition, each transmitter pressure reading is individually temperature-compensated
within the specified operating temperature range.
The transmitters have up to three mechanical relays which can be used for process control, for example
interlocking valves or pumps. The analog voltage output can be interfaced to external analog equipment for
pressure readout or controlling.
Sensor technology
The transmitters have a single MEMS Pirani (MEMS = Micro-Electro-
Mechanical-System) sensor element whose measurements are based
on measurement of thermal conductivity. The MEMS Pirani sensor
consists of a silicon chip with a heated resistive element forming one
surface of a cavity. A cover on top of the chip forms the other surface of
the cavity. Due to the geometry of the sensor, convection cannot take
place within the cavity and consequently the sensor is insensitive to
mounting position. Gas molecules are passed by diffusion only to the
heated element where the heat loss of the gas is measured. The
sensor element is very robust and can withstand high G-forces and
instant air inrush.
Applications
The transmitters can be used in many different vacuum applications within e.g. the industrial application, research
and development, semiconductor, analytical and coating industries:
General vacuum pressure measurement
Fore line and roughing pressure measurement
Gas backfilling measurement and controlling
Mass spectrometer control
Activation of UHV gauge
System process control
Sense abnormal pressure and take appropriate security measure using relay set points
Control system pressure
P/N: 230045V02 and 230047V02 contain Parylene-HT® coated sensors.
Parylene-HT® is a conformal coating with excellent gas barrier properties with no outgassing. Sensors coated with
Parylene-HT® offer better resistance against various corrosive gases compared to the standard MEMS Pirani. The
coating covers the entire sensor chip, including wiring. Hence the only material exposed to the process gas is the
Parylene-HT® coating. Please contact Application support for further information.
Disposal
The TTR 91 N and 96 N transmitters are manufactured according to the RoHS directive.
For the benefit of the environment, at the end of life of the transmitter, it should not be disposed in
the normal unsorted waste stream. It should be deposited at an appropriate collection point or
facility to enable recovery or recycling.
Temperature measurement
resistors Rt
Silicon cover
Silicon cover
Measuring
resistors Rm
Attention
!
Parylene-HT® is a trademark of Specialty Coating Systems, Inc

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Technical Data
Measurement principle: Thermal conductivity according to a MEMS Pirani sensor
Measurement range (N2and Air): 5×10-5 to 1000 mbar
Accuracy(1) (N2): 5×10-4 to 1x10-3 mbar: ±10% of reading
1×10-3 to 100 mbar: ± 5% of reading
100 to 1000 mbar: ± 25% of reading
Repeatability(1) (N2): 1×10-3 to 100 mbar: ± 2% of reading
Supply Voltage: 9 –30 VDC
Power consumption: < 1.2 Watt
Fuse (thermal recoverable): 200 mA
Analog output (100 Ω impedance): 0.61 –10 VDC, Log. 1.286 VDC/decade
Analog output resolution: 16 bit
Analog output update rate: 16 Hz
Sensor fail, analog output: 0.5 V
Materials exposed to vacuum (2):
P/N: 230035V02 to 230043V02: 304 stainless steel, sealing material FPM
P/N: 230045V02, 230047V02: 304 stainless steel, sealing material FPM, Parylene-HT®
Setpoint relay(s):
P/N: 230035V02 to 230038V02: 0
P/N: 230040V02 to 230047V02: 2
Setpoint relay range: 2×10-4 to 1000 mbar
Setpoint relay contact rating: 1A / 30 VDC/AC (resistive load)
Setpoint relay response time: < 100 ms
Setpoint relay contact resistance: 100 mΩ (max)
Setpoint relay contact endurance: 100,000 cycles (min) (30 VDC/1 A load)
Setpoint relay contact endurance: 2,000,000 cycles (min) (30 VDC/0.2 A load)
Internal volume:
P/N: 230035V02, 230040V02, 230045V02: KF16 2.80 cm3
P/N: 230036V02: CF 16 3.71 cm3
P/N: 230038V02, 230043V02: NPT 1/8” 3.04 cm3
P/N: 230037V02, 230047V02: CF 16 (bakeable) 23.14 cm3
Housing material: Stainless steel 304
Weight:
P/N: 230035V02, 230040V02, 230045V02: 168 g
P/N: 230036V02: 195 g
P/N: 230038V02, 230043V02: 183 g
P/N: 230037V02, 230047V02: 250 g
Maximum allowed pressure: 6 bar
Operating temperature: 0 to 40 °C (32 to 104 °F)
Bakeout temperature (Power off) (3): 85 °C (185 °F)
250 °C (482 °F) (only for P/N: 230037V02, 230047V02)(3)
Filament temperature: 35 °C above ambient temperature
Ingress Protection Rating: IP40
Leak rate < 5∙10-9 mbar∙l/s
(1) Accuracy and repeatability values are typical values measured in Nitrogen atmosphere at ambient temperature
after zero adjustment.
(2) For the full list of all materials exposed to process gases please contact Leybold.
(3) This bakeout temperature is only allowed at the end of the CF 16 flange. The temperature of the transmitter
must not exceed 85 °C (185 °F). Thus, it is not recommended to thermally insulate or directly heat the transmitter
and flange during bakeout.

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Dimensions
[mm]
P/N: 230035V02 to 230047V02
Flanges:
KF 16
CF 16
CF 16 (bakeable)
NPT 1/8”

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Accessories and replacement part numbers
Part
Part no.
TTR 91 N, DN16 KF
230035V02
TTR 91 N, DN16 CF
230036V02
TTR 91 N, DN16 CF, bakeable
230037V02
TTR 91 N, 1/8" NPT
230038V02
TTR 91 N, DN16 KF, 2SP
230040V02
TTR 91 N, 1/8" NPT, 2SP
230043V02
TTR 96 N C, DN16 KF, 2SP
230045V02
TTR 96 N C, DN16 CF, bakeable, 2SP
230047V02
Display One
230001
Display Two
230024
Display Three
230025
Graphix One
230680V01
Graphix Two
230681V01
Graphix Three
230682V01
Cables Type A 5 Meter
12426
Cables Type A 10 Meter
230012
Cables Type A 15 Meter
12427
Cables Type A 20 Meter
12428
Cables Type A 30 Meter
12429
Cables Type A 50 Meter
12431
Cables Type A 75 Meter
12432
Cables Type A 100 Meter
12433
Spiral tube DN 16 ISO-KF
230082
Centering Rings (Stainless Steel 1.4305) with O-Ring,
DN16 KF
88346
Centering Rings (Stainless Steel) with Sintered Metal Filter,
DN16 KF
88351
Clamping Rings (Aluminium), DN16 KF
18341
Centering Ring with fine filter DN 16 ISO-KF
88396
CF Bolts with double nut M4+20
83887
CF Copper gaskets DN16 CF
ES83941

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Transmitter Installation (Mechanical)
Conforming utilization
The transmitter is intended for measuring pressure.
The transmitters are intended for use in relatively clean environments.
The transmitter can only be used by persons who have suitable technical training and the necessary
experience or who have been instructed by the end-user of the product.
Always ensure that all vacuum sealing items and surfaces are clean, without damage and free of particles.
Use a cable with strain relief to ensure proper electrical connection and to reduce stress on the connectors.
To comply with EN61326-1 immunity requirements, use a braided, shielded cable.
Non-conforming utilization
The transmitter cannot be used for measurements other than described in this manual.
The transmitters are not intended for use in dirty and corrosive environments
Do not use the transmitter in presence of flammable gases or other explosive environments.
Do not install substituted parts or perform any unauthorized modification to the instrument.
The transmitter is not intended for use above maximum allowed pressure.
Process compatibility
The TTR 91 N and TTR 96 N transmitters are intended for use in relatively
clean environments. The transmitters cannot be used in corrosive
environments like a semiconductor etch process chamber where aggressive
gases like fluorine are used. The Parylene-HT® coated sensors (P/N:
230045V02, 230047V02) offer improved corrosion resistance. The Parylene-
HT® coating can be compromised when exposed to aggressive environments
for long periods or in high concentration corrosive environments. Furthermore,
environments used for stripping Parylene-HT®, like a reactive oxygen plasma,
will also damage the sensor over time.
If the transmitter is located close to a gas source connection like a flow
controller or leak valve, the transmitter pressure measurement can be higher
than the actual chamber pressure. Location close to a pumping system
connection can cause a lower pressure measurement than actual chamber
pressure.
The transmitters and their sensor design can be mounted in any orientation without compromising accuracy.
However it is not recommended to mount the transmitters upside down, as dust and dirt might fall into the sensor.
Explosive Environments
The sensor filament is kept at a low temperature of only 35 °C above ambient temperature, however in case of
malfunction in the sensor element can exceed normal operating temperature and consequently the transmitter
should not be used in explosive environments.
Do not use or install the transmitter where the following conditions occur:
- Temperatures lower than 0 °C or higher than 40 °C
- Corrosive or explosive gases
- Direct sunlight or other heat sources
!
Not recommended
Caution
!
!

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Temperature
The transmitters have an active and individual sensor temperature compensation circuit that ensures accurate
measurement in a wide temperature range.
For best measuring performance avoid large temperature gradients and direct cooling like air-condition air stream
or heating like a pump exhaust stream.
Bake out
The transmitter electronics can withstand maximum 85 °C (185 °F) when the power is turned off.
The bakeout temperature of 250 oC (482 °F) (for P/N: 230037V02, 230047V02) is only allowed at the end of the CF
16 flange. The temperature of the transmitter must not exceed 85 oC (185 °F). Thus, it is not recommended to
thermally insulate or directly heat the transmitter and flange during bakeout.
Contamination
Locate and orient the transmitter where contamination is least likely. The sensor has a low filament temperature of
only 35°C above ambient temperature; therefore, the sensor is less prone to contamination by cracking products
from fore vacuum pump oil.
Vibrations and instant air inrush
The sensor element is extremely robust to mechanical forces like vibration and G-forces. The sensor element
cannot be damaged by fast and repeated pressure cycles or instant inrush of air.
Vacuum connections
The transmitters are available with different types of vacuum fittings. When mounting the transmitter, always
ensure that all vacuum sealing items and surfaces are clean, without damage and free of particles. Do not touch
the vacuum flange sealing surface.
Pressure range
The standard TTR 91 N and TTR 96 N THERMOVAC Transmitters are internally sealed with elastomer FPM
sealing and are intended for use in the pressure range 5×10-5 to 1000 mbar. If used in UHV applications the out
gassing rate of FPM can be too high.
If the transmitter is backfilled with a liquid like pump oil the sensor element is likely permanently
damaged. The transmitter cannot be cleaned using solvents.
If the transmitter will be exposed to pressures above atmospheric pressure make sure that proper
vacuum fittings are used. Ensure that the internal system pressure is at ambient pressure
conditions before opening the vacuum system and removing any connections.
Attention
Caution
!
!
!
!

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Transmitter Installation (Electrical)
Use a cable with strain relief to ensure proper electrical connection and to reduce stress on the connectors.
To comply with EN61326-1 immunity requirements, use a braided, shielded cable. Connect the braid to the metal
hoods at both ends of the cable with the end for power supply connected to earth ground.
Ground loops, differences of potential, or EMC problems may affect the measurement signal. For optimum signal
quality, please do observe the following notes:
Use an overall metal braided shielded cable. The connector must have a metal case.
Connect the cable shield to ground at one side via the connector case. Make sure the connector case has
direct contact to the cable's shield on its whole circumference. Do not connect the other side of the shield.
Connect the supply common with protective ground directly at the power.
Use differential measurement input (signal common and supply common conducted separately).
Potential difference between supply common and housing ≤18 V (overvoltage protection).
The power supply input is 9 to 30 VDC. The power supply input is protected by an internal thermal fuse. The fuse is
self-recoverable; do not replace it. Damage may occur to the circuitry if excessive voltage is applied, polarity
reversed, or if a wrong connection is made.
If using the analog voltage output, connect the positive analog out and negative analog out pins to a differential
input voltmeter or an analog-to-digital (A/D) converter. Do not connect the negative side of the analog output to the
negative side of the power supply input or to any other ground. Doing so will cause half of the power current to flow
through this wire. Measurement errors in the output voltage may be seen due to the voltage drop from this current.
The longer the cable, the worse the error will be. Do not connect the set point relay terminals to the analog output.
Correct connection of analog output to floating input
Incorrect connection of analog output to non-floating input
Ensure a low impedance electrical connection between the transmitter body and the grounded
vacuum system to shield the sensor from external electromagnetic sources.
Ensure that the analog output is connected to floating input.
Attention
!
!

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Input/Output Wiring
To comply with EN61326-1 immunity requirements, use a braided, shielded cable. Connect the braid to the metal
hoods at both ends of the cable with the end for power supply connected to earth ground.
Part Numbers: 230035V02 to 230038V02:
I/O Connector (8 pin RJ45/FCC68)
PIN Description
1
Power + (9-30 VDC)
5
Analog Output -
2
Power return - (GND)
6
Not Connected
3
Analog Output +
7
Not Connected
4
ID-Resistor, 27 kΩ (±1%)
8
Not Connected
Part Numbers: 230040V02 to 230047V02:
I/O Connector (8 pin RJ45/FCC68)
PIN Description
1
Power + (9-30 VDC)
5
Analog Output -
2
Power return - (GND)
6
Relay Setpoint 2 (closing contact)
3
Analog Output +
7
Relay Setpoint 1 (closing contact)
4
ID-Resistor, 27 kΩ (±1%)
8
Relay Setpoint 1 and 2 Common

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Setpoint relays
The TTR 91 N and TTR 96 N THERMOVAC transmitters have up to three mechanical relays that can be used for
controlling external process equipment. The relay has closing and breaking contacts and the contacts are rated 30
VDC, 1 A, resistive load. For further information about the setpoint adjustment, refer to chapter 6.
Inductive relay load
Special precautions should be taken when driving inductive loads with the relay contact. When an inductive load
like a solenoid is energized, the in-rush current is significant higher than the regular load current. In-rush currents
exceeding the relay contact rating can cause reduction of relay contact life time or contact reliability.
When a solenoid is de-energized, the collapsing magnetic field can cause significant voltage spikes. These spikes
can couple capacitively from cable to cable and interfere with measuring electronics or transmitter signal.
An arc suppression network, as shown schematically to the right, is
recommended. The values of the capacitance C and the resistance R
can be calculated by the following equations:
C = I2/(1 x 107) R = E/ Ia
where:
C is in Farads. R is in ohms
I is DC or ACpeak load current in amperes. E is DC or ACpeak source voltage in volts
a = 1 + (50/ E)
Note that Rmin = 0.5 Ω and Cmin = 1×10-9 F, D is a fast transient suppression diode.
Setpoint functionality
The set point relays can be activated either above or below the set point values. The graphs below show the
different relays stages in either below or above configuration. The NC contact will always be closed in case of
power failure.
To adjust the set point relays to above or below switching functionality you must follow the procedure like described
in chapter 6.3.
It is important to understand that when the signal is declining during adjustment you will set the below function and
if the signal is increasing you will set the above function.
To change the direction of signal adjustment, you must keep the button pressed until reaching top or low end of the
set point range, then the signal will change its direction.
Driving inductive loads via the setpoint relay contacts requires de-energizing spike protection.
Inadequate protection can cause permanent damage to the transmitter or interfere with the analog
output signal.
Always ensure that inductive in-rush currents do not exceed relay contact rating.
When using the setpoint relay to control process equipment always take appropriate precautions to
prevent system damage in case of transmitter power failure. The NC contact will be closed in case
of transmitter power failure.
Critical
!
Critical
!

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Operations
Pressure output
The TTR 91 N and TTR 96 N THERMOVAC transmitters can provide pressure measurement output as an analog
voltage value.
The analog output provides a 16 bit resolution. Refer to chapter 5.2 for further details.
Measuring noise
External sources can interfere with the sensor signal and cause noise on the signal. The low measuring range is
most sensitive to measuring noise due to low signal levels.
When designing external pressure control loops make sure that external equipment, like a pumping
system, is not damaged if the transmitter output enters Sensor defect mode or in case of power
failure.
When designing pressure data collecting software and controlling loop make sure that the software
does not interpret a communication error as a valid pressure value.
Caution
Caution
!
!
!
!

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Analog output
The TTR 91 N and TTR 96 N THERMOVAC transmitters provide a voltage output a function of pressure. The
output is 1.286 VDC/decade.
Conversion formulae:
Pmbar = 10((Vout –6,143)/1,286)Vout = log10 (Pmbar) x 1.286 + 6.143
P [mbar]
Analog out [V]
P [mbar]
Analog out [V]
P [mbar]
Analog out [V]
P [mbar]
Analog out [V]
5.00E-05
0.6119
6.00E-03
3.2857
8.00E-01
6.0184
1.00E+02
8.7150
6.00E-05
0.7137
7.00E-03
3.3718
9.00E-01
6.0842
2.00E+02
9.1021
7.00E-05
0.7998
8.00E-03
3.4464
1.00E+00
6.1430
3.00E+02
9.3286
8.00E-05
0.8744
9.00E-03
3.5122
2.00E+00
6.5301
4.00E+02
9.4892
9.00E-05
0.9402
1.00E-02
3.5710
3.00E+00
6.7566
5.00E+02
9.6139
1.00E-04
0.9990
2.00E-02
3.9581
4.00E+00
6.9172
6.00E+02
9.7157
1.20E-04
1.1008
3.00E-02
4.1846
5.00E+00
7.0419
7.00E+02
9.8018
2.00E-04
1.3861
4.00E-02
4.3452
6.00E+00
7.1437
8.00E+02
9.8764
3.00E-04
1.6126
5.00E-02
4.4699
7.00E+00
7.2298
9.00E+02
9.9422
4.00E-04
1.7732
6.00E-02
4.5717
8.00E+00
7.3044
1.00E+03
10.0000
5.00E-04
1.8979
7.00E-02
4.6578
9.00E+00
7.3702
6.00E-04
1.9997
8.00E-02
4.7324
1.00E+01
7.4290
7.00E-04
2.0858
9.00E-02
4.7982
2.00E+01
7.8161
8.00E-04
2.1604
1.00E-01
4.8570
3.00E+01
8.0426
9.00E-04
2.2262
2.00E-01
5.2441
4.00E+01
8.2032
1.00E-03
2.2850
3.00E-01
5.4706
5.00E+01
8.3279
2.00E-03
2.6721
4.00E-01
5.6312
6.00E+01
8.4297
3.00E-03
2.8986
5.00E-01
5.7559
7.00E+01
8.5158
4.00E-03
3.0592
6.00E-01
5.8577
8.00E+01
8.5904
5.00E-03
3.1839
7.00E-01
5.9438
9.00E+01
8.6562
0
1
2
3
4
5
6
7
8
9
10
11
1 E-05 1 E-04 1 E-03 1 E-02 1 E-01 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04
Analog Out, VDC
Pressure, mbar

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Sensor gas dependence
The sensor technology is based on measurement of thermal conductivity and consequently its reading depends on
gas and gas concentration.
The transmitter sensor is per factory default calibrated for Nitrogen gas and shown below is the TTR 91 N and
TTR 96 N MEMS Pirani reading for different gas types. Be aware that when measuring in environments where
other gases than nitrogen (calibration gas) are present, the readings can deviate from the true pressure.
In the range below 1 mbar, the pressure indication is linear. For gases other than air, the pressure can be
determined by means of a simple conversion formula:
   
For which:
Gas type
Calibration factor C
Valid range (mbar]
He
1.4
3∙10-3 to 0.3 mbar
Ar
1.57
10-3 to 1 mbar
H2
0.84
3∙10-3 to 0.2 mbar
Air, O2, CO, N2
1
3∙10-3 to 0.3 mbar
These conversion factors are average values.
1E-4
1E-3
1E-2
1E-1
1E0
1E1
1E2
1E3
1E-4 1E-3 1E-2 1E-1 1E0 1E1 1E2 1E3
Actual gas pressure, mbar
Transmitter reading, mbar
Air (50%
Humidity)
Argon
Helium
Hydrogen

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Functions
The user switch, red/green LED-ring/LED status indicator and connector can be found at the top of the transmitter.
LED-ring/LED status indicator
The LED-ring/LED will indicate the status of the transmitter by showing a certain color-code:
LED-ring/LED
Transmitter status
Solid green
Normal operation
2 sec. red
Power on sequence
2 sec. red
User switch disabled
Continuously RED
Transmitter defect
Off
Power off
Other
Relates to configuration of vacuum-zero/full-scale
adjustment or relay Setpoint adjustment see chapter 6.2.
User switch
Red/green LED-ring
I/O Connector

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Vacuum-zero/full-scale adjustment and setpoint adjustment
It is possible to perform vacuum-zero/full-scale adjustment (Zero/FS) by using the user switch.
Setpoint adjustments with the user switch can only be performed for transmitters with P/N: 230040V02 to
230047V02.
Zero adjustment before operation is recommended to obtain best measurement performance in the lowest part of
the measuring range. Vacuum-zero adjustment is not required for measurements above 5x10-4 mbar. However,
drift can occur over time and periodic vacuum-zero adjustments are then recommended to optimize measurement
performance.
MEMS Pirani-sensor vacuum-zero/full-scale (Zero/FS) adjustments
The vacuum-zero adjustment function changes the MEMS Pirani measurement offset at low pressure. Temporary
or permanent shift in zero offset can be caused by contamination, corrosion, electrical noise interference and
temperature.
The MEMS Pirani full scale adjustment allows the user to adjust the MEMS Pirani full scale reading Atmospheric
adjustment can only be executed with air or Nitrogen.
It is possible to perform vacuum-zero/full-scale adjustments of the MEMS Pirani-sensor by using the user switch.
See chapter 6.3.
To obtain best measuring performance, it is recommended that the transmitter is evacuated to a
pressure below 1×10-5 mbar before executing zero adjustment of the MEMS Pirani sensor.
Zero adjustment of the MEMS Pirani sensor can be executed at pressures higher than 1×10-5 mbar,
but this can cause inaccurate reading.
If the pressure measured by the transmitter is higher than approximately 1x10-2 mbar, then the zero
adjustment cannot be executed. If the zero adjustment failed, the LED-ring/LED will flash red three
times.
Zero adjustment only changes the low measuring range and will have no influence on measuring
errors in the range from 1×10-2 mbar and above.
Atmospheric adjustment only changes the high measuring range and will have no influence on
measuring errors in the range below 10 mbar.
Before performing the atmospheric adjustment, vent transmitter to Nitrogen or air pressure of 1000
mbar. The transmitter will only accept full-scale adjustment when the pressure readout is within 600
to 1000 mbar. Note that if the adjustment is performed at a true pressure different from 1000 mbar,
it can cause measurement deviations in the upper part of the measuring range.
Attention
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Attention
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Caution
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