Inficon Sensistor ISH2000 HySpeed User manual

EN
Operating Instructions
Publication: INFICON AB - nina60e1-c (1204) - All information can be modified without prior notice
Hydrogen Leak Detector
Sensistor ISH2000

Hydrogen Leak Detector Sensistor ISH2000 - Operating Instructions
2 OP-Sensistor ISH2000-EN
EN

Hydrogen leak detector Sensistor ISH2000 - Operating Instructions
OP-Sensistor ISH2000-EN-201203 1
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Contents
1 User information ........................................................................................................................... 3
1.1 Notes and safety notices..........................................................................................................3
1.2 Document outline....................................................................................................................3
1.3 Conventions used in this book.................................................................................................3
2 Description of equipment............................................................................................................. 4
2.1 Sensistor ISH2000....................................................................................................................4
2.2 Sensistor ISH2000C .................................................................................................................4
2.3 Sensistor ISH2000P..................................................................................................................5
3 Controls and connections.............................................................................................................7
3.1 Display ....................................................................................................................................7
3.2 Push-buttons ........................................................................................................................... 7
3.3 LEDs ........................................................................................................................................ 8
3.4 Ports and connections .............................................................................................................8
4 Precautions .................................................................................................................................. 10
4.1 When working with gas ........................................................................................................10
4.2 Hydrogen Tracer Gas for leak detection ................................................................................. 11
4.3 Interferences .........................................................................................................................11
5 Working principle....................................................................................................................... 12
5.1 Gas Sensor Technology .........................................................................................................12
5.2 Condition for leak detection .................................................................................................. 12
5.3 Leak detection modes............................................................................................................12
6 Operating the detector............................................................................................................... 13
6.1 To Detect leaks.....................................................................................................................13
6.2 To Locate Leaks ....................................................................................................................13
6.3 To Quantify Leaks .................................................................................................................14
7 Calibrate the leak detector......................................................................................................... 15
7.1 Introduction ..........................................................................................................................15
7.2 Calibration reference ............................................................................................................. 15
7.3 Calibration procedure............................................................................................................15
7.4 Reference value with reference leak....................................................................................... 16
7.5 Reference value with reference gas........................................................................................ 16
8 Reference section ........................................................................................................................ 17
8.1 Menu system.........................................................................................................................17
8.2 Engineering format................................................................................................................17
8.3 Change Test Mode ................................................................................................................ 18
8.4 Calibration ............................................................................................................................18
8.5 Detection Mode Settings .......................................................................................................21
8.6 Analysis mode .......................................................................................................................23
8.7 APC Settings ......................................................................................................................... 25
8.8 Display Settings .....................................................................................................................26
8.9 General settings .................................................................................................................... 27
8.10 Service Settings ..................................................................................................................... 28
8.11 Combined Mode ................................................................................................................... 29
8.12 Probe ....................................................................................................................................29
8.13 Probe Control Port................................................................................................................. 30
8.14 Printer port............................................................................................................................33
8.15 Sensistor ISH2000P installation ..............................................................................................38
8.16 Default parameters................................................................................................................40
9 Trouble-shooting......................................................................................................................... 42
10 Sensistor ISH2000 specifications................................................................................................43
11 Spare parts and accessories........................................................................................................ 45
12 Support by INFICON.................................................................................................................... 46
12.1 How To Contact INFICON ......................................................................................................46
12.2 Returning you instrument to INFICON....................................................................................46
13 Declaration of conformity .......................................................................................................... 47
14 Recycling ...................................................................................................................................... 48

Hydrogen leak detector Sensistor ISH2000 - Operating Instructions
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EN Welcome to Sensistor ISH2000
Dear customer,
You have just bought an INFICON Hydrogen Leak Detector Sensistor ISH2000. The
Sensistor ISH2000 is an extremely sensitive and selective detector for hydrogen gas (H2).
It is especially designed for leak detection using Hydrogen Tracer Gas (Hydrogen diluted
with Nitrogen down to a safe concentration) which is the most effective and economical
tracer gas for leak testing.
Sensistor ISH2000 detects hydrogen in air at atmospheric pressure with no need for
vacuum pumping. It is especially suitable for applications where high sensitivity and
selectivity is required in combination with simplicity, reliability and low cost.
This product complies with the requirements of European
Directives, listed in the Declaration of Conformity found on
page 47 in this document. These Directives are amended by
Directive 93/68/E.E.C (E.C. Marking).
Copyright/Intellectual property
The use of INFICON AB products are subject to copyright and
intellectual property rights in force in any jurisdiction.
All rights reserved, including copying this document in whole
or in any part without prior written authorization from
INFICON AB.
Though INFICON AB believes reasonable efforts have been
made to ensure the accuracy of the information contained in
the document, it may include inaccuracies or typographical
errors. INFICON AB reserves the right to change the
information inside the document without further notice.

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1 User information
Read this user manual carefully before using the Sensistor ISH2000.
1.1 Notes and safety notices
This manual contains warnings and cautions concerning the safe use of the product.
See definitions below.
Note: A Note is used to indicate information that is important for trouble-free and
optimal use of the Sensistor ISH2000.
1.2 Document outline
The document is devided in two main parts:
• Getting started
• Reference section
The Getting started part consists of step by step case examples, explaining how to
use the Sensistor ISH2000 in a variety common situations. The Reference section
consists of in depth explanation and additional information, which completes the
user manual with all relevant information.
1.3 Conventions used in this book
In this user manual the following text style (hardware command) is used for
references to hardware commands or button labels, while this text style (software
command) is used for references to software commands and menu choices.
WARNING!
Warning indicates a hazardous situation which, if not
avoided, could result in death or serious injury. It is
important not to proceed until all stated conditions
are met and clearly understood.
CAUTION!
Caution indicates a hazardous situation which, if not
avoided, could result in minor or moderate injury. It is
important not to proceed until all stated conditions
are met and clearly understood.
NOTICE!
Notice indicates instructions that must be
followed to avoid damage to the Sensistor
ISH2000 or other equipment.

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EN 2 Description of equipment
Sensistor ISH2000 can be purchased in one of three versions. A desktop model
(Sensistor ISH2000), a battery operated model (Sensistor ISH2000C), and a panel
mount model (Sensistor ISH2000P).
2.1 Sensistor ISH2000
Sensistor ISH2000 is equipped with a number of powerful functions making it very
easy to integrate in a semi or fully automatic test system. The functions range from
output of all necessary status signals and printer/communication port to an
advanced Active Probe Control system (APC). This makes the detector capable of
controlling advanced sample collecting devices down to simple test fixtures.
Fig 2-1. The desktop model consists of seven parts.
2.2 Sensistor ISH2000C
The battery operated model, Sensistor ISH2000C, has all the Sensistor ISH2000
features apart from the APC system. This means that only passive probes (for
example Hand Probe P50) can be used. This is due to power management control.
Item Description
1Detector unit
2Hand Probe P50 (shown) or Active Probe with
sensor
3Probe cable C21
4Power cable (the power cable is country specific
and may differ)
5User manual (not shown)
6User manual CD (not shown)
7Product return form (not shown)
1
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The battery, a Li-ion battery at 14.8 V, can not support the current required to
operate external probes.
On the display (in Detection and Analysis Mode) a symbol in the upper right corner
shows the battery charge status. Sensistor ISH2000C will operate for 14 hours on a
fully charged battery with screensaver and mute function. And 9 hours without
screensaver and mute function.
One hour charging will give about one hour of operating time. This can be done
when necessary, but it is important to regularly fully charge the battery.
Fig 2-2. The battery operated model consists of seven parts.
2.3 Sensistor ISH2000P
The panel mount model, Sensistor ISH2000P, has identical features of the Sensistor
ISH2000.
The difference is that the Sensistor ISH2000 can be installed in the operator’s panel
or any other flat surface. Also it operates on +24 VDC. Mounting brackets and a
panel rubber seal are delivered with the detector. See “Sensistor ISH2000P
installation” on page 38.
Item Description
1Detector unit
2Hand Probe P50 (shown) or P50-Flex
3Probe cable C21
4Battery charger (the battery charger are country
specific and may differ, not shown).
5User manual (not shown)
6User manual CD (not shown)
7Product return form (not shown)
1
2
3

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EN Fig 2-3. The panel mount model consists of seven parts.
Item Description
1Detector unit
2Brackets (not shown)
3Screws (not shown)
4O-rings seal (not shown)
5User manual (not shown)
6User manual CD (not shown)
7Product return form (not shown)
1

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3 Controls and connections
The controls and connections are discussed and shown in this chapter.
Fig 3-1. Sensistor ISH2000 controls and indicators.
3.1 Display
The display shows:
• indicator bar in Detection Mode and the figures in Analysis Mode.
• seven main menus. Their positions are indicated on a horizontal scale. Change from
one menu to another using the < and >buttons.
• main menus have submenus, which are also indicated by horizontal scales and can
be selected using the <and >buttons.
• scales for setting numeric values, languages, etc.
• messages.
Sensistor ISH2000C:
• A battery status indicator in the upper right corner.
3.2 Push-buttons
The functions of the push-buttons are shown at the lower edge of the display. In this
manual the buttons are numbered, from left to right, 1, 2, 3, and 4. The push-buttons
are used to:
• Change from one menu item to another using the < and >buttons.
• Press Enter to move down to the nearest submenu.
• Press Save to save the set value.
• Press Undo to restore the previously set value.
• Press Esc to move up to the nearest higher level(s).
Item Description
1Display
2Loudspeaker
3Control push-buttons
4Earphone socket
5Probe connector
6LEDs
1
1
2
45
6
3 3 3 3

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EN 3.3 LEDs
The two LEDs indicate the status of the instrument as follows:
• Green flashing slowly, during warming up phase.
• Green fixed light indicates that instrument is ready and hydrogen signal is below
Reject Level limit.
• Red fixed light together with Reject on display means the instrument has detected a
leak larger than the set Reject Level limit.
• Red flashing rapidly, check message on screen. (See “Trouble-shooting” on
page 42.)
3.4 Ports and connections
The ports and connections are shown in Figure 3-2 below.
Sensistor ISH2000
Fig 3-2. Sensistor ISH2000 ports and connections.
NOTICE!
Always connect all four wires to the Power connector to
24VDC in order to operate.
Item Description
1Printer port
2Probe control port
3Fuse
4Power switch
5Power input, 100-240 VAC
6Screw hole for mounting plate
1
2
3
4
5
6
1
2
3
4
5
6
Rear View

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Sensistor ISH2000C
Fig 3-3. Sensistor ISH2000C ports and connections.
Sensistor ISH2000P
Fig 3-4. Sensistor ISH2000P ports and connections.
Item Description
1Power switch
2Printer port
3Battery charger
4Screw hole for mounting plate
1
2
3
4
Sensistor ISH2000C Rear View
Item Description
1Probe connection
2Ground screw
3Power connector
4Probe control port
5Printer port
Sensistor ISH2000P Rear View
123
4
5

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EN 4 Precautions
Read this user manual carefully before using the instrument. Hydrogen Leak
Detector Sensistor ISH2000 is extremely selective. Only Hydrogen Sulphide
(extremely toxic) gives a comparable response to hydrogen.
4.1 When working with gas
The normal risks associated with working with all compressed gases must be
considered.
Before connecting tracer gas: confirm that the connectors or test object is designed
for working at the test pressure.
Note: INFICON AB can not take any responsibility for the consequences arising from the
inappropriate use of certain test pressures.
WARNING!
Pure hydrogen is a flammable gas. Only use
ready-made Hydrogen Tracer Gas of 5%
Hydrogen in Nitrogen. This is a standard
industrial gas mixture used in various industrial
applications.
Note: Whenever the word Hydrogen is used in this
manual it implies that the hydrogen gas is safely
mixed with Nitrogen in the proportions 5% H2-
95% N2.
WARNING!
Since the tracer gas mix contains no oxygen,
releasing large amounts of gas in a confined
space may lead to asphyxiation.
WARNING!
Compressed gases contain a great deal of stored
energy. Always carefully secure gas bottles
before connecting pressure regulator. Never
transport gas bottle with the pressure regulator
fitted.
WARNING!
Pressurising objects at too high pressures can
result in a burst object. This in turn can result in
serious injury or even death.
Never pressurise objects that have not
previously been burst tested or otherwise
approved for the chosen test pressure.

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Pressure shocks might cause strong sounds which can cause impairment of hearing.
Check that all relevant legislation and safety standards are complied with before
putting Sensistor ISH2000 into service.
4.2 Hydrogen Tracer Gas for leak detection
When pure hydrogen gas is released in air its flammability range spans from 4% to
75% of hydrogen in air. Below 4% there is insufficient chemical energy available for
a flame to occur. Above 75% hydrogen there is not enough oxygen left to support a
flame.
When, for example, a mixture of less than 5.5% hydrogen in nitrogen mixes with air
there is not sufficient energy to support a flame, irrespective of the ratio of air-to-
gas.
When a mixture of more than 5.5% hydrogen in nitrogen is released into air there is
a region of ratios of air-to-gas where the mixture is flammable. When, for example,
a mixture of 10% hydrogen in nitrogen mixes with air there is still very little energy
available. Only in exceptional circumstances can a flame be self-supporting.
However, such mixtures cannot detonate.
4.3 Interferences
Most tracer gas methods suffer from some sort of interference. Either the detector is
sensitive to other gases or vapors, or there are other sources of the gas present to
which the detector is sensitive.
Some examples of possible hydrogen sources:
• Engine exhaust
• Battery charging stations
• Cigarette smoke
• Breathing air
• Human flatulence
• Scratching on aluminum surfaces
WARNING!
Hydrogen/nitrogen mixtures containing
approximately more than 15% hydrogen can
detonate when mixed in certain proportions
with air.
NOTICE!
Never make your own mixtures. Only use ready-
made mixtures or use a certified hydrogen/
nitrogen mixture mixer installed by your gas
supplier.

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EN 5 Working principle
5.1 Gas Sensor Technology
The Sensistor ISH2000 leak detector is using an extremely sensitive hydrogen gas
sensor based on a microelectronic field effect transistor (MOS-FET).
The gas sensitivity appears when hydrogen absorbs into the sensor through a metal
alloy (metal hydride) layer.
Only hydrogen can diffuse into the metal and this makes the sensors practically
insensitive to other substances that do not contain free hydrogen molecules.
The signals from the sensors are processed by a microprocessor which also controls
the sensor temperature with high accuracy, and other sensor diagnostics in order to
ensure perfect functionality. It also automatically compensates for background gas.
5.2 Condition for leak detection
To use the leak detector the test object must be filled and pressurized by tracer gas
(95% N2/ 5% H2) to get a gas flow through the leak. The tracer gas is a standard
welding gas of industry quality, easy to obtain at low cost. The generic name is
Forming Gas. Appropriate gas filling equipment can be obtained from the leak
detector supplier.
Be careful of how tracer gases are handled after use. Released tracer gas
contaminates the surrounding air with hydrogen and can complicate the following
measurements for a time. Ensure that the tracer gas is ventilated away from the
target area, preferably to the outside of the building.
5.3 Leak detection modes
The detector operates in three modes:
• The leak locating mode (Detection Mode), mainly used for detecting and locating
leaks but not quantifying them.
• The hydrogen measurement mode (Analysis Mode) measures the concentration of
hydrogen.
• The Combined Mode, (default mode) which is a combination of Detection and
Analysis mode.
The Detection Mode operates continuously while the Analysis Mode determines the
hydrogen concentration (and calculates a corresponding leak rate) in a step
measurement. Detection Mode gives no numbers. It therefore needs no actual
calibration. The sensitivity of the sound signal and the moving bar on the display is
set manually or automatically, see below.
When using the instrument in Analysis Mode, it must be calibrated as described. See
“Calibrate the leak detector” on page 15 in order to give correct figures.

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6 Operating the detector
6.1 To Detect leaks
If all you wish to do is to detect the presence of a leak, that is, find out whether there is
a leak or not, then use the Detection Mode (or use the detection bar in Combined
Mode). The definition of Leak/No Leak will then simply be ”A leak is a leak when it can
be detected by the detector, set to a specific sensitivity”.
To set up:
The operation in Detection Mode is not quantitative. The audio and visual signal
will increase and decrease with the gas concentration. Therefore, there is no actual
calibration to be done, but rather a setting of the sensitivity to a desired level.
A typical set-up procedure for Detection Mode is:
• Set up a reference leak which corresponds to the smallest leak you wish to detect.
• Put the probe close to the reference leak and note approximately what reaction you
get (no reaction, small, medium, high, full scale) within the first few seconds.
• Set the sensitivity. This can be done permanently under the menu Detection Mode
Settings or temporarily as a Direct Sensitivity Adjustment on the display (unless
you have set this function to OFF under the Detection Mode Settings menu).
There is also an Auto ranging function which can be selected under the Detection
Mode Settings menu.
Note: If the Detection Mode is used and the alarm function is required to be
activated at a particular calibrated level, then the unit must be calibrated in
accordance with the instructions, see “Calibrate the leak detector” on
page 15. The reason for this is that the alarm is based on the Analysis Mode
when the Detection Mode is displayed.
6.2 To Locate Leaks
Note: The Detection Mode (or use the detection bar in Combined Mode) is used
to locate leaks. This mode is semi-quantitative, that is, it gives an audio and
visual signal which increases as a leak is approached (a higher gas
concentration) and decreases as you move the probe away from the leak. It
does not display figures. In this mode of operation leaks can easily be detected
using a sensitivity which can be preset. See “Sensitivity” on page 25 and
“Direct Sensitivity Adjustment” on page 25.
Leaks can be located very accurately, even when there are other leaks nearby. If, for
example, you are trying to locate a leak on a product and the product has a major
leak, then you will get an audio signal as soon as the probe is placed close to the
product. When the probe is moved around and over the product, the signal will
increase as the probe approaches the leak. If the signal goes out of scale, simply
reduce the sensitivity setting to bring the signal within the scale. Working with the
sensitivity setting this way you will be able to locate multiple leaks that are in close
proximity to each other.
Note: Working inside a confined space such as, for example, a cabinet or a narrow
passage on a combustion engine there is a risk that the background
concentration accumulates to levels close to the upper detection limit of the
detector. In such case it will not be possible to locate leaks as easily as in open
spaces.

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EN Hint: It is good practice to detect a leak, locate it, and immediately remove the probe
to avoid saturation. The probe is not damaged by the exposure but it will recover more
slowly. After excessive exposure it will be less sensitive for a short period of time.
6.3 To Quantify Leaks
The Analysis Mode (or use the analysis figures in Combined Mode) is used for
measuring the size of a leak (or the concentration of a gas sample). To be able to do
this measurement and obtain correct values, the instrument must first be calibrated
using the calibration function.
In the Analysis Mode the detector determines the gas concentration from the
change, as the probe goes from being exposed to background to being exposed to a
certain gas concentration. The detector does not continuously monitor the gas
concentration but takes just one reading instead. Another suitable alternative name
for this mode could be Sampling Mode. It is important to keep this in mind when using
the detector in this mode.
In Analysis Mode the probe should be moved directly from a background situation to
the test point. The size of the leak in PPM, or any other selected units, is shown on the
display. The probe can and should be removed from the measuring point as the
measured value steadies and remains on the display. The period during which the
measured value is displayed can be adjusted in the Analysis Mode Settings menu.
The leak detector operates in the range 0.5 - 2000 ppm H2giving linearity between 0.5
and 500 ppm. To obtain greatest accuracy over this range, follow the calibration
recommendation. See “Calibrate the leak detector” on page 17.
CAUTION!
• Do not open detector! Service of this equipment may only be carried out by ser-
vice organisations authorised therefore by INFICON, Sweden.
• If the detector gets outer damage it must be controlled and repaired by service
organisation authorised by INFICON.
• Do not expose the probe to a hydrogen concentration higher than 0.1% when
the instrument is not put into operation, this might damage or destroy the probe
sensor.
• When the instrument is put into operation the sensor withstands temporary
exposure to hydrogen concentration up to 100%. Avoid long exposures to high
concentrations.

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7 Calibrate the leak detector
7.1 Introduction
The leak detector is the instrument and the probe together.
This section of the user manual consists of step by step examples about how to
calibrate the detector in the most common cases. For more about the calibration
routine see the reference section.
The instrument must be calibrated by using the integrated calibration function to
make sure it displays the correct values in Analysis Mode. After calibration the
instrument will show the correct measured values on the display in Analysis Mode.
The calibration parameters will be stored into the probe.
7.2 Calibration reference
There is a possibility to calibrate the detector by Reference Gas or Reference Leak.
A Reference Gas contains a well-defined concentration of Hydrogen gas in ppm
mixed by air or some inert gas. A Certificate will normal follow the gas bottles.
Reference Gas can be ordered from local gas suppliers.
A Reference Leak is a well –defined gas leak, and should be feed by same gas as
using in the detection test and with a gas pressure that is defined in the Reference
Leak certificate. Reference Leak can be ordered from the detector provider.
Choose a calibration reference size, as follows recommendations:
• Same or higher than the Reject Level (but maximum 10 times higher)
• in one of the following ranges:
5 to 400 ppm H2
1x10-5 to 4x10-3 cc/s (mbarl/s) defined for air
3 to 120 g/a defined for R134a
Please contact the provider of the detector for help to select optimal calibration
reference for your application.
7.3 Calibration procedure
Before calibration, the Reference Value in the Calibration Menu must be set. See “With
reference gas” and “With reference leak” below.
When calibrating, expose the probe to the background air then do the following
steps:
1. First Menu then Calibration/Calibrate/Enter.
2. Push the Start button or push the probe button.
3. Expose the probe for the reference gas/leak
The probe does not have to be exposed to the to the calibration gas during the
whole Calibration Time (the time set in the Calibration menu while the bar is moving).
The instrument only measures the change as the probe goes from the background
air to calibration gas.
While the calibration time bar is moving, the probe should be exposed to the
calibration gas or referenece leak. Then the display shows Detecting Gas and gives
sound signals. Save or repeat the calibration routine until you can save the

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EN calibration. If the calibration is not saved, the instrument will revert to the previous
value after one minute.
Note: You will need to repeat the calibration 2-3 times to get Calibration OK after
changing setup or probe.
• Allow at least 30 seconds between each calibration for best accuracy!
• If the message “No Gas or Unstable Signal” is displayed repeatedly - go back to
Detection Mode and check functionality.
• If Repeat Calibration is displayed then this means that the measured value
deviated more than 10% from the previous calibration. Repeat the calibration
procedure.
Also set the Analysis Unit to the same as the Reference Value. If you want to use
another unit you have to put a recalculation number into Correlation Value which
describes the relationship between the different units.
7.4 Reference value with reference leak
When measuring leak flow you will, in normal cases, calibrate the detector with a
reference leak.
Set the Reference Value equal to the calibrated flow of your reference leak. This
value can be found on the calibration certificate issued for the leak. Also set the
Reference Unit to the same unit as that used to express the leak rate of the reference
leak.
Example: Reference leak rate is 4.2E-5 mbarl/s.
1- Set Reference Value = 4.2E-05.
2- Set Reference Unit = “mbarl/s
Note: Feed the reference leak at the pressure stated on the calibration certificate. If
another pressure is used you must correlate the resulting flow and use this
value as Reference Value.
Note: The concentration of the reference leak should always during the calibration
procedure be within the concentration range of 5 PPM - 400 PPM H2.
7.5 Reference value with reference gas
When measuring hydrogen concentration (instead of leak flow) in most cases you
will calibrate the detector to a reference gas with a known concentration.
Set the Reference Value equal to the Hydrogen concentration in your reference gas.
This can be found on the certificate of analysis issued for the gas. Also set the
Reference Unit to the same unit as that used to express the leak rate of the reference
leak.
Example: Reference gas contains 10 PPM Hydrogen in synthetic air.
1- Set the Reference Value = 10
2- Set the Reference Unit = “PPM”

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8 Reference section
This section of the user manual consists of an in-depth explanation and additional
information, which completes the user manual with all relevant information.
8.1 Menu system
The menu system is designed as a tree structure similar to that used in mobile
telephones. The display shows all the levels when browsing down through the
menus so that you can always see exactly where you are.
Fig 8-1. Sensistor ISH2000 controls and indicators.
To enter the menus, press Menu (button 4). Press <and >(button 2 and button 3) to
choose between main menus.
If no setting is made in a menu or its submenus within 60 seconds, the instrument
will revert to the Detection Mode/Analysis Mode.
Button functions
The buttons may change functions in different menues. Always read the text, just
above the buttons in the display, for the button functions.
All changes in values are valid only when saved using the Save button (button 4).
Use the Undo button (button 1) to delete a change in value and revert to the
previous setting.
Use the Esc button (button 1) to browse backwards through the menus to the start
position Detection Mode/Analysis Mode.
To change quickly from Detection Mode to Analysis Mode or vice versa, press button 4
three times in succession.
8.2 Engineering format
Some of the parameters of the detector are written in engineering format. This
format can represent a very wide range of numbers from very small to very large
numbers.
The following examples describes the format used in the detector:
1.00E+01 = 1.00 x 101= 10
1 2 3 4

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1.25E-02 = 1.25 x 10-2 = 0.0125
8.3 Change Test Mode
Choose the measuring method you will use in the menu Change Test Mode. There
are three different methods to choose:
• Analysis Mode
• Detection Mode
• Combined Mode
See Reference section for a description of the functions.
8.4 Calibration
Calibrate
The instrument must be calibrated by using the integral calibration function to
ensure it displays the correct values in Analysis Mode/Combined Mode. After
calibration the instrument will show the correct measured values on the display. The
calibration parameters will be stored into the probe.
Calibration intervals
Calibration is a natural part of leak measurement and an important factor in quality
assurance. It is impossible to specify an exact requirement for the interval between
the calibrations because the applications for which the instrument is used can vary
considerably.
There will be some oxidation of the probe sensor, which reduces the sensitivity, if
the probe sensor:
• is not subjected to gas for a lengthy period or
• is exposed to a very small gas concentration (less than 10 PPM) with long
intervals between exposure.
If the instrument is subjected to a very large gas concentration over a long period, a
certain amount of insensitivity can occur directly afterwards. This saturation can
make it difficult to detect very small leaks. Therefore, make it a habit of removing
the probe from the measuring point as soon as the measured value is displayed. This
gives the detector an opportunity to recover.
Sensitivity too low for reject level
The Detector will warn if sensitivity of sensor is too low to safely detect a leak equal
to the set Reject Level limit. The warning can be ignored and calibration updated
and the CAL_CONF output will be set.
High signal! Check reference!
The Detector will warn if the calibration signal is unreasonably high. This can occur,
for example, if 5% tracer gas mix has been used instead of proper reference gas or if
the reference leak has an extra non-intentional leak. The warning can be ignored
and the calibration updated and the CAL_CONF output will be set.