Divesoft HE/02 User manual

MANUAL
He/O2Analyzer
HE/O2ANALYZER USER MANUAL
Date of issue: 6 March 2019
HW 2.5, FW 2.26
Authors: Adam Procháska, Jakub Šimánek, Aleš Procháska
Published by Divesoft s.r.o.

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Content
1. About firmware and hardware versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Measuring principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Description of the analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Operating the analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Measuring O2and He concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Display modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1 Calibration of the oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Other functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1 Continuous analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.2 Gas mixing solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.3 Gas mixing simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.4 Ambient pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8. Special accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1 Flow regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.2 Voltage measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.3 Resistance measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.4 Emergency disconnection of filling station . . . . . . . . . . . . . . . . . . . . . . . . . 17
9. Set-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.1 Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.2 Measurement units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.3 Mixing of gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.4 Continual analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10. Charging and battery status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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11. Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.1 Battery replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.2 Oxygen sensor replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.3 Flow adjusting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11.4 Disassembly of the instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
12. Connecting to a computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
13. Defects and removal thereof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
13.1 Error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
13.2 Instrument malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
14. Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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Safety warning
This analyzer is designed for measuring the content of oxygen and helium in an air-oxygen-
helium gas mixture. It cannot be used to analyze mixes containing other gases, including, for
instance, mixes prepared using anything but pure gases or mixes in which air has been replaced
with pure nitrogen (without atmospheric argon).
The physical and chemical principles of the sensors used do not guarantee that the sensors
will be selectively sensitive to a specific gas (oxygen, helium); there are a number of gases
to which the sensors respond. Therefore, the gas composition shown by the analyzer does
not mean by itself that the real composition of the mix is equal to the displayed values. The
displayed mix composition is invalid unless the mixing technology ensures that there are no
other gases present in the mix except air, pure oxygen and pure helium.
The analyzer is not a certified measuring instrument. The results of measuring are only informa-
tive and it is not possible to use such results where a certified measuring instrument is required.
When analyzing mixes in situations where the incorrect composition of the mixes could cause
material damage, injury to health or threaten human health or life, for example in the case of
breathing mixes for diving, the results of the analysis may not be used as confirmation of the
correct mix composition. In these cases, the analyzer can only be used as an aid for increasing
the probability that such incorrect mix composition will be detected before its use. The
correctness of the mix composition must be established by the technology used to prepare it.
The correct preparation of breathing mixes for diving (nitrox – oxygen-enriched air, trimix –
a mixture of air, oxygen and helium, heliox – a mixture of oxygen and helium) requires special
knowledge and experience which is possible to gain, for example, through an appropriate
course. A failure to apply such knowledge can lead to an incorrect mix, even though the results
of the analysis are seemingly correct. Such a situation can also be the result of a failure to
take into account the influence of temperature and compressibility, an insufficient blending of
the mix and other factors.
Please remember that the analyzer can be broken or damaged and that the oxygen sensor is by
its nature subject to ageing and thus its properties deteriorate.
Therefore always verify the measured data in another way, such as by precise preparation of the
mix, another analytical method, etc. In addition, the measured value must be subject to critical
assessment using a common-sense approach and if it differs from the allowable variation of
mixing accuracy, it must be considered invalid.

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1. About firmware and hardware versions
The He/O2analyzer is equipped with a microprocessor whose program (firmware) is
continuously updated. This manual is for firmware release 2.26., but the manual can be applied
to any hardware version. Manual is primarily written for hardware version 2.5. Older versions
of hardware analyzers are not equipped with certain elements and are therefore not able to
perform some functions described in the manual.
Hardware limitations
2.5 Full functionality
2.4 Full functionality
2.3 Lack of barometer. In case the ambient pressure changes significantly a new O2
calibration is necessary.
9V battery only.
2.2 Lack of barometer
9V battery only
LCD display (limited readability in bright light)
2.1 Lack of barometer
9V battery only
LCD display (limited readability in bright light)
Some signals are not present on system connector (DVI)

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2. Measuring principle
The described measuring principle is valid only for mixes of air, oxygen and helium.
An electrochemical sensor is used to determine the oxygen content. The voltage at the
sensor’s output is proportional to the oxygen content in the analyzed mix. The sensor has
a limited service life and the proportionality of the dependence of voltage on the oxygen
content changes over time; therefore, it has to be regularly calibrated. It is possible to choose
between single-point, two-point and three-point calibration. Single-point calibration is fast,
especially if air is chosen as the calibrating mix. For greater accuracy of the measurement,
two-point calibration is used with two different mixes, typically air and pure oxygen. For
strongly hypoxic mixes, i.e. mixes containing less than approximately 15% oxygen, three-point
calibration is recommended. In this case, the third calibration gas should be a gas with zero
oxygen content, i.e. pure helium or argon.
Helium content is determined on the basis of measuring the speed of sound in the analyzed
mix. The speed of sound depends on the content of helium and oxygen, and the temperature
of the mix. The dependence of the speed of sound on pressure is small and can be disregarded
under normal atmospheric pressure.
At 0º C the speed of sound is approximately 970 m/s in pure helium, 330 m/s in air and
315 m/s in pure oxygen. Raising the temperature by one degree increases the speed of sound
by 0.175 %. The speed of sound in the mix is described by a non-linear function of temperature,
oxygen content and helium content.
The content of helium is determined by measuring the speed of sound, temperature of the
mix and the content of oxygen. When measuring the concentration of helium, it is therefore
necessary to have the oxygen sensor correctly calibrated or to know the oxygen content and
enter it into the instrument.
The speed of sound is measured directly as the time it takes for an acoustic impulse to travel
between two microphones. This measurement is performed alternately in both directions to
make it possible to eliminate the influence of the gas flow-rate in the probe on the calculation.
The acoustic impulses are heard as weak “clicks” from the probe in the helium-measuring
mode.
Gas is delivered to the analyzer from a sampler connected to the compressed-gas tank and the
gas flow is controlled using a nozzle to provide the volume needed for the analysis.

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3. Description of the analyzer
The analyzer is manufactured from high-strength aluminum alloy, which guarantees stable
dimensions and resistance against mechanical damage. The surface is hard-anodized to
protect it against scratching.
On the front side, the analyzer features a membrane keypad and an OLED display on which the
measured values are shown.
Measured gas is fed into the analyzed-mix inlet on the back of the analyzer and passes through
the helium-concentration sensor. From there, it enters the oxygen-sensor block and is expelled
into the air by the mix exhaust. The rated flow of the analyzed mix is 0.2 L/min
The analyzer is powered by a standard nine-volt battery (type 6F22) or by an external power
supply connected to the left side. The battery is accessible from the bottom by removing the
two screws of the retaining cover.
On the back of the analyzer, there is a connector for attaching auxiliary devices (for measuring
pressure, tank temperature, electrical voltage, etc.). A USB connector is located on the side for
transferring data to a computer and for updating firmware.

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4. Operating the analyzer
The analyzer is operated using the keys on its
front panel.
It is activated by pressing the ON/OFF key for
approximately one second. Upon activation,
an automatic check of the instrument is
performed and the analyzer automatically
switches to the measuring mode.
When this key is pressed, the firmware version code and serial number of the analyzer are
displayed. If you need to read this information, just hold the key down longer when activating
the unit.
The analyzer is deactivated by pressing the ON/OFF key for about one second again.
The MENU key displays the available options. The menu changes in individual measuring modes,
depending on the functions relevant to the applicable mode.
The key is used to enter the selected menu item, confirm a changed value or perform the
prepared action. The selected menu item can also be called up by repeatedly pressing the
MENU key.
The ESC key is used to exit the menu or return from the value editing mode without saving the
changed value.
The and keys are used to browse the menu or change the value of a number above the
cursor.
The MODE key is used to change the display mode or to change the cursor position in the
number editing mode.
Other functions of the keys are described in the relevant chapters.

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5. Measuring O2and He concentration
The flow limiter with nozzle is used in the basic configuration (see illustration).
Attach the sampler to the compressed gas bottle and use the hose to connect it to the
analyzer. The hose is slightly inserted into both components.
The analyzer switches into the helium and oxygen measuring mode upon activation, so there is
no need for you to set up anything. Open the valve on the bottle to let the gas flow in. The gas
composition is displayed after approximately 5 – 10 seconds. If the pressure inside the bottle
is distinctly lower than 200 bars, the gas flow through the sampler will be slower and the
measuring result will take somewhat longer to determine.
With the key, you can suspend and, by pressing it again, resume measuring. When measuring
is suspended, the last measured values remain displayed. During measuring, the key can be
used for temporarily increasing the brightness of the display to maximum (e.g. if the display is
exposed to sunlight).
When the measuring is completed, close the valve on the tank and by loosening the discharge
valve (generally 1/2 turn suffices) discharge the excess pressure of the gas so that the flow
limiter can be unscrewed from the tank valve.
Warning: Do not unscrew the discharge-valve spindle completely; a steal ball is contained
inside which upon opening could be expelled and cause injury or be lost.

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6. Display modes
Upon activation, the analyzer is normally in the O2/He measuring mode, in one of the two
display formats.
The basic format shows the oxygen and helium content in the mixture in percent in separate
lines and, for information, also the temperature at which the gas was measured.
After the measuring begins, the helium concentration may appear in square brackets for
several seconds in the basic format. This means that the result is interim, with lower accuracy.
When the brackets disappear, the accuracy of the result is final.
In case of a measuring error, for instance at a pneumatic shock in the inlet hose, the value of
the measured helium concentration disappears for the time of duration of the error state.
The well-arranged format shows the composition in a way used by divers to call the mixtures:
— Air: air with the oxygen content between 20.5 % and 21.5 %.
— EAN, for instance EAN 36, is air enriched with oxygen, in this case up to 36 % oxygen.
— TMX, for instance TMX 18/45, is trimix or the mixture of air, oxygen and helium, in this
particular case containing 18 % oxygen and 45 % helium.
— Heliox, for instance Heliox 16 % O2, is a mixture of oxygen and helium.
— Foul Air, for instance Foul Air (10 % O2), is foul or vitiated air with a reduced oxygen content.
It cannot be mixed with gases designed for preparation of breathing mixes commonly avail-
able to the diver (air, oxygen, helium); therefore, its presence indicates a problem. This may
include ongoing corrosion inside the bottle or contamination of the mix with argon, carbon
dioxide or another gas. Such air cannot be used for breathing under any circumstances.
In addition to the mix composition, this well-arranged format shows approximate values of the
maximum operating depth (MOD) and an equivalent narcotic depth (END).
MOD indicates the depth to which the diver can dive for a short time under otherwise ideal
conditions. The limit of partial oxygen pressure equal to 1.6 kPa is used in the calculation,
and seawater and the static pressure at sea level are taken into account. This reading is for
orientation only, and for an actual dive it must be calculated using the data of the specific dive.

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The following formula is used for the calculation:
MOD =
P
max
ρg
RO2–PO
where P
max
is the maximum allowable partial oxygen pressure, chosen as 160,000 Pa
P
0
is the static pressure at sea level, 101,325 Pa
R
O2
relative molar concentration of oxygen in the interval 0 to 1
ρ is the seawater density, 1028 kg m−3
g is the standard acceleration of gravity, 9.80665 m s−2
Warning: The maximum operating depth (MOD) calculated for an actual dive is usually lower
than the depth indicated by the analyzer.
END is the depth at which the narcotic effect of the mix on the diver is identical to that of air.
It is specified in the percentage of a dive depth with air, i.e. for instance the END of 45 % means
that at a depth of 100 m with an analyzed mix, the diver will perceive the same narcotic effects
as if diving to 45 m with air. There are a number of various formulas for the calculation of END,
each giving different results. The value displayed by the analyzer uses only one of them and is
used for orientation purposes only. For an actual dive, it is necessary to calculate the END using
the data of the specific dive and the tested formulas of your preference.
The following formula is used for calculation:
END = 100 − 77 RHe
where RHe is the relative molar concentration of helium in the ration 0 to 1
The formula is based on the following conditions:
— relative narcotic potential of nitrogen = 1
— relative narcotic potential of oxygen = 1
— relative narcotic potential of helium = 0.23
Warning: The equivalent narcotic depth (END) indicated by the calculation is for orientation
purposes only and may differ from the END values calculated using other methodologies.
Warning: To determine the END and MOD values, always use the procedures and formulas that
you learned in specialized courses of diving with mixes. The values indicated by the analyzer
are for orientation purposes only and are not sufficient for correct dive planning.

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6.1 Calibration of the oxygen sensor
The oxygen sensor’s properties change over time and it is therefore necessary to recalibrate it.
We recommend that such calibration be performed at least once a month. Analyzer with the
older version than 2.4, the calibration is always necessary when changing altitude. Version 2.4
has a built-in barometer sensor, which corrects itself. If you require the most precise results,
calibrate the sensor before each measuring.
Calibration of the sensor is performed as either single-point or two-point or three-point. During
single-point calibration, the content of oxygen in air, which is known and constant (20.95 %), is
measured by the sensor. The calibration constant of the sensor is set so that the instrument
displays 21.0 % (after rounding).
Two-point calibration proceeds in the same manner as single-point calibration, but uses two
calibration gases – pure oxygen and air. Two-point calibration is more arduous as it requires
the use of oxygen. However, it provides more precise results during measuring.
Thee-point calibration is recommended for measuring hypoxic mixes, containing less than
approximately 15 % oxygen. In this case, the third calibration gas should be a gas with zero
oxygen content, i.e. pure helium or argon.
Calibration of the oxygen sensor is started by pressing the CAL key at any time during the
measuring.
As the first step of calibration, we must choose between single-point, two-point or three-point
calibration using the and keys and confirm the selection using the key.
It is then necessary to choose the oxygen content in the calibration mixture.
The oxygen content is adjusted by tenths of a percent by pressing the key (to increase
the content) or the key (to decrease the content). Use the MODE key to choose whether to
make adjustments by tenths, whole units, or units of ten percentage points. Upon setting the
desired values, confirm the data using the key.
For quickly setting typical values when setting the oxygen content it is possible to use the CAL
key, which sets the oxygen content at 21 % in the case of the first calibration point or 100 % at
the second point and 0 % at the third point.

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Upon setting and confirming the calibration of gases, calibration of the sensor begins.
The current calibration point, sensor voltage in millivolts and the temperature of the gas
appear on the display.
After the temperature and voltage have stabilized (however, at least after ten seconds),
the STABLE prompt appears, which means that it is possible to confirm the performed
calibration using the key. If the measured values change before the key is pressed,
the STABLE sign disappears and calibration proceeds until further steady values are attained.
If multi-point calibration is set up, then calibration according to the other gases proceeds
similarly.

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7. Other functions
7.1 Continuous analysis
The Menu/Continual Analysis option activates the function of continuous-filling monitoring.
This mode makes it possible to set up the upper and lower limit of oxygen and helium content.
The analyzer continuously measures the concentration of these components and if the preset
limits are exceeded, it makes a beeping sound. This mode is applied when the analyzer is used
as a safety component during continuous nitrox filling, where a defect of the mixing apparatus
could cause increased oxygen concentration potentially resulting in a fire or an explosion of
the compressor.
In the mode for continuous filling, the limit values can be changed after pressing the MENU
button.
7.2 Gas mixing solver
When the Menu/Gas mix solver option is selected, the gas-mixing solver function is activated.
The solver computes the procedure for mixing the required gas mix of up to three gases.
It can even include the remaining mix in the bottle to be filled in the calculation. The gases
are displayed in the following order: the remaining gas in the bottle, added mix 1–3, the
required mix. For each mix, the composition, volume of the bottle (the actual, “water” volume
of the bottle is specified) and gas pressure in the bottle are specified. If the volume of the
gas is unlimited (for instance, if supplied by a compressor at a constant pressure), enter the
bottle volume as zero. The mix composition may be entered either manually (after pressing
the , or the analyzer can be switched to the measuring mode by pressing the key and
the relevant mix can be measured directly. After pressing the CAL is necessary to change the
values press .Then you can enter values . Press MENU to move the cursor in the
order. Confirm the selected value . After the data are entered, initiate the calculation using
Menu/Solve (since it is first option, you can just press button twice). The calculation may
take up to one minute. Upon completion, results are displayed in one of the three possible
forms, which can be switched between using the key (see the example).
Example
There is remaining air with the pressure of 120 bars in the twin bottles with the volume of
2 × 12 liters (total volume of 24 liters). The required mix is trimix 18/40 with the required

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pressure of 200 bars. You have fifty-liter distribution bottles containing oxygen and helium and
a compressor with the output of 330 bars. Enter:
A: Air 24L 120
1: He 50L 200
2: O250L 200
3: Air 300
D: 18.0/40.0 24L 200
and start the calculation. When the calculation is completed, the following data are displayed:
Disch. to 79.5 bar
He to 159.5 bar
O2to 173.2 bar
Air to 200.0 bar
meaning that the twin should be discharged to the pressure of 79.5 bars, then He added until
the pressure of 159.5 bars is achieved, then oxygen added to 173.2 bars and, finally, air added
to reach 200 bars. When the MODE key is pressed, the same result is displayed; however, it is
expressed in pressure to add or to discharge:
Disch. -40.5 bar
Add 80.0 bar He
Add 13.7 bar O2
Add 26.8 bar Air
or decrease the pressure by 40.5 bars, increase the pressure by 80 bars by adding helium,
add 13.7 bars of oxygen and 26.8 bars of air. The last mode is similar, but as it is designed for
gravimetric filling (using a chemical balance), the amount of gas is specified in kilograms:
Disch. -1.2382 kg
Add 0.3392 kg He
Add 0.4669 kg O2
Add 0.8230 kg Air
Please note that the solver takes into account the pressure drop in the gas charging bottles;
therefore it does not try to recommend adding oxygen to reach 200 bars (which would be
impossible anyway, given the limited oxygen supply); rather, it allows air to be partly discharged
and oxygen is only added to reach the realistic 173.2 bars, with the rest of the air to be added
by the compressor. At the same time, however, the solver saves the mix already contained in

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the bottle to the maximum possible extent; therefore, it does not let it discharge completely.
Instead, only the necessary part of the mix is discharged.
7.3 Gas mixing simulation
Option Menu/Gas mix simulator is for Gas mix simulator function. Simulator will compute
mixture content mixed up to from four gases. At every mixture is displayed composition
and quantity of added gas in pressure units. You can enter mix composition manually (by
pressing ) or switch to measurement mode by pressing and directly measure concrete
mixture. Calculation of final mixture proceed continuously and mixture constitution is
displayed on last row. Input values is the same as in the previous case.
7.4 Ambient pressure
Analyzer is equipped with a barometric pressure sensor. Thanks to this device can be calibrated
for the atmospheric conditions and altitude. The atmospheric pressure and altitude can be
displayed in the menu ambient pressure. Altitude is calculated from the ambient pressure and,
depending on atmospheric conditions may differ from reality.

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8. Special accessories
8.1 Flow regulator
For taking a gas sample for analysis, it is possible to use the flow regulator. It is used in
a similar manner as the limiter. However, thanks to the use of a reduction valve, there is no
decrease in flow and the measuring period is thus extended even with lower pressure in
the tank. Its use is therefore suitable in filling stations and dive centers in which the content
of half-empty tanks is checked.
The regulator is constructed from the Divesoft M12 modular system. The illustration
shows only one of the possible configurations. Because the leads of the distribution
block are equivalent, it is possible to freely reconfigure individual elements according to
the user’s needs. Similarly, it is possible to replace the limiting nozzle with a reduction valve
without the necessity of buying a full regulator assembly.
The regulator is connected similarly as the limiter. Besides the tank valve, it is possible to close
off the gas output directly with the gas-output cut-off
Warning: Over-tightening of the gas-output cut-off can damage or prematurely wear out
the reduction-valve seat.
8.2 Voltage measuring
Optional measuring cables can be attached to the analyzer to measure electric voltage. After
the “V” connector is plugged in, the analyzer automatically switches to the mode of a simple
low-voltage voltmeter. The voltmeter is designed to be used as a tool when repairing diving
equipment in the field (diving lamp, storage or plain battery check, etc.) The maximum allowed
DC voltage is 40V (any polarity) or 28V AC with sinusoidal wave. The effective value (RMS) is
measured for AC voltage.
Warning: The voltmeter must not in any case be connected to the power distribution network
or to any equipment connected to mains!
Warning: If the voltmeter is exposed to the mains voltage, the analyzer will be destroyed and/
or personal injury or death due to electric shock may occur!

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8.3 Resistance measuring
Optional measuring cables can be attached to the analyzer to measure electrical resistance.
After the connector “Ω” is plugged in, the analyzer automatically switches to the mode of
a simple low voltage ohmmeter. The ohmmeter is designed to be used as a tool when repairing
diving equipment in the field (diving lamp, storage or plain battery check etc.). The measuring
range is 0–1000 Ω. By pressing the MODE key, the ohmmeter can be switched to the acoustic
signaling mode for resistance below 200 Ω(the ring tone).
Warning: In any case, the ohmmeter must not be connected to the power distribution network
or to any equipment connected to mains!
Warning: If the ohmmeter is connected to the mains voltage, the analyzer will be destroyed
and/or personal injury or death due to electric shock may occur!
8.4 Emergency disconnection of filling station
To the analyzer can be attached cable for disconnection of nitrox or trimix continual filling
device. After cable connection analyzer automatically will switch to the watch continual filling
mode. On last row display will display current state relay outputs in form Re:123. At shutdown
some relay is his number replaced by dash, for example Re:–23.
Standardly is measured content of O2and He. Metering is possible to extend by pressure
sensor, e.g for pressure measuring on compressor outlet, and external sensor of temperature
in −55–125 °C.
At overrun some of monitored values will immediately switched off relay 1. If value is not
returned to the allowed limits within 30 seconds, will switched off also relay 2. Same progress
is also when analyzer battery are discharged.
When analyzer is switched off, all relays are immediately also switched off.
Preset delay and limiting values you can change after pressing button MENU.
Recommended cable wiring: relay 1 for alerting and relay 2 for disconnection of filling station.
Maximum relay contacts load is 24V / 500mA. Realy must not be in any case used directly for
shut down of compressor, but only for controll circuit (e. g. power relays).

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Warning: Power circuit wiring and circuits connected to electric power must be made expertly
and in agreement with valid safety standards, regulations and law.
Warning: At power circuits and circuits connected to electric power incorrectly wiring the
analyzer will be destroyed and/or you risk serious injury or death by electric power!

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9. Set-up
9.1 Preferences
It is possible to change select properties of the analyzer in the basic mode (measuring of
He/O2) in Menu/Preferences. Individual parameters have the following significance:
Brightness of the display in the scale of 1 to 127. The selection of low brightness (1) preserves
the battery; the highest brightness (127) is suitable for use in strongly lit places. For
temporarily increasing the display’s brightness, simply hold down the pressed .key.
When activating the Heighten brightness option, the brightness is automatically increased to
maximum if the analyzer is powered with an external power-supply adapter.
The option O2cell used is activated as standard. When deactivating, the O2value is ignored
and replaced with the value shown in the following O2substitute parameter. This option allows
emergency use of the analyzer with a worn-out oxygen sensor for measuring the concentration
of helium. In such a case, the correct setting of the oxygen concentration in the analyzed mix
increases the precision of measuring the concentration of helium (on the order of tenths of
a percent).
Averaging activates the calculation of the moving average from the set number of values of
the He concentration. The number of averaged values is set with the Values to avg. parameter.