Sub Aqua Alpha-1 User manual

Alpha-1 Oxygen ~Analyser
• Water R es istant Aluminium Ca se
• Easy Calibration
• Fast Sample an d Recovery
• Extended Sensor Life
• Accurate to 0.1 %

Alpha-1 Control Solutions Oxygen Analyser
The Alpha-I Oxygen Analyser has been designed by divers for divers.
The Analyser is very easy to use and is highly accurate. The Oxygen Sensor has been s
pe cially developed for the
Alpha- I Analyser and together with the electronics is temperature stable over the range
of -20 to +50 degrees
Celsius.
The Sensor is fitted with a Sealing Cap which when fitted extends the life
of the Sensor. The Sensor life is
approximately 2
years+ in normal air (20.9%) and greater when the cap is fitted.
The robust aluminium case is sealed to IP65 (sprayed
jets of water), the Sensor Sealing Cap should always be fitted
ifthe unit is likely to get wet. Do not puncture or remove the white membrane in the sensors gas inp ut port.
WARNING the universal Sampling Adapter can not withstand high pressure s. Only fit to a partially open
cylinder valve once steady low flow has been obtained. NEVER fit to a closed valve and then try to obtain a
sample as the Sensor can be dama
ge d be yo nd repair by too high pressures. The correct method of use is fully
described
in the Operating Instructions below.
Operating Instructions
I - Remove the Sensor Sealing Ca p and turn on the Analyser by pressing the on/off switch. Allow 3-5 minutes for
the Sensor to stabilise to normal air.
The display will remain constant once stabilised.
Calibrate the Analyser by adjusting the
Ca libration Control until a reading of20.9% is displayed.
IMPORTANT Ca libration should be performed out doors in Dry, Fresh Air. The nominal percentage of Oxygen
indoors is very seldom 20.9% and can be as low as
19 .9%. A normal air fill serves as an exce ll ent calibration
reference
if indoor calibration has to be carried out.
2 - Slowly open the cylinder valve of the cylinder to be sampled to test the action of the valve. The valve must be
able to be adjusted to allow a constant minimal flow. With practise this is nearly always achievabl
e.
3 - Fit the universal Sampling Adapter to the partially open valve as shown in the photo 's bel ow :
Universal Sampling Adapter Fitted to an 'A' Clamp Valve Fitted to a DIN valve
Finally check that a low volume constant
fl ow of gas can be heard venting
from the Sensor Flow adapto
r. It is important to note that too high a fl ow
level can over pressurise & destroy the sensor
Se nsor Flow Adaptor.

4 - The last action is to push the Sensor Flow Adapter into the Oxygen Sensor to commence sampling th e gas.
After approx
im ately 45 seconds the Analyser display will stabilise and indicate th e percentage of Oxygen in the
gas. Accuracy can be confirmed by removing the Sensor Flow Adapter from the Sensor and allow approximately
another 45 seconds for the analyser to return
to th e original calibration setting +- 0.I%.
(remember to u se exactly the sa me conditions used to obtain the original calibration)
5 - Replace the Sensor sealing cap when not analysing. Leave the unit switched on and observe the display which
will start
to increase as the cap creates a seal. Cease tightening when the display has increased. DO NOT over
tighten the cap as this is not required and a poor seal may result
ifthe internal 'O' ring is co ll apsed.
6 - Switch
off the analyser by pressing the on/offswitch.
Battery Replacement
A low battery
is indicated by the display showing a battery symbol at the left hand top corner of the display
Remove the 4 x screws that secure the rear cover and remove the cover. The battery will been seen in the lower part
of the case. The battery is a 9 vo lt PP3(MN1604) type and it is recommended that an alkaline type is used.
The easiest way
to replace the cover is to position the sealing correctly on to the cover, then invert the analyser case
onto the cover, and then turn the unit over and replace the screws. Take care not
to over tighten the screws as the
aluminium case
is quite soft.
Se nsor Replace ment
The Sensor will require replacement one day. The replacement Sensor should be obtained from the store that
supplied the analyser. This can easily be fitted into the unit
by fo ll owing the in structions supplied with each
replacement Sensor. To ensure continued accuracy, it
is essential to fit an original Alpha- I replacement Sensor.
Warranty Terms
The Sensor is covered by a l year warranty and the Analyser is covered by a 2 year warranty commencing from
date
of purchase. Please be sure to retain your receipt as this serves as the warranty document.
Exclusions from
Warranty Th e following are not included in the warranty period s:
-Sensor over pressure damage. Providing that the Operating Instructions are followed correctly This ca n not
occur.
-Mechanical damage to the Analyser and fittings and th e Sensor gas input port membrane
-
Lngress of water into the Analyser resulting from an incorrectly fitted or damaged rear cover sealing gasket.
-Ingress
of water into the Analyser ifthe IP 65 rating has been exceeded.
-Loss
of fittings, hoses etc.
Removal or defacement
of the Sensor id entification label w ill invalidate the Sensor Warranty.
Specifications
Range
Li nea ri ty
Sensor Resolution
Sensor L
if e
Se nsor Response to Ta rget (T)
Working Temperature Range
Storage Temperature Range
Disp
la y
Calibration
Environmental Seal
Battery
Weight
Sensor Replacement
Support Telephone Number
0-100% Oxygen
Linear through out ran
ge
0.1% (see below)
2 Years + (average diver use)
> 50 seconds
0 to +50 degrees Cel si us
-20
to + 50 degrees Cels iu s
3.5 digit LCD IOmm character height
Manual
to ambient Dry, Fresh a ir to 20.9% for EAN 's up to 60%.
Above 60% sampling, calibrati on to 10 0% Oxygen.
IP65 -Sprayed jets of water
PP3 (MN 1640) Alkaline
420 grams
By end user or dive store
+44(0)
148 9878055

Alpha-1 Analyser re-Calibration
The Analyser will requi re internal secondary calibration before thf: Sen sorex pire s. This wi ll bec ome apparent as
the 20. 9% calibration setting will not be achievable. A steady lowf :r value will in ste ad be di s pl ay ed. Calibration is
performed as follow s:
1. Remove the rear cover.
2. The internal re-calibration control is located at bottom centre port ( red) in the se aled elf: ctronics module. This
is a fine multi-tum control and will need to be turned sever al ti me s.
3. Tum the front user calibration co ntrol fully clockwise to obtain t he maximum reading.
4. Adjust t
he internal calibration control until a nominal reading of2 2. 2% is displayed (see bel ow for variations).
l)fJ>ORTANT Carry out the re-calib1 ·a tion outdoot:ti!!..Qry, Fre sh Ai.£,
The nominal setting of 22 . 2% varks according to the local atmospheric press ure. This can be obtained fr om an
accurately set barometer or by con tacting a loc al we ather station or one of the mim y we ather websites now on line.
For
UK us ers we recommend the fo llowing website: http: // www.weather.CO.u k/ the lo c al atmospheric
pressure
is obtained by entering th •e postcode of your loc ation.
The no
minal atmospheric pressure is 1013mb. Each 5mb variation requires a .1% offset to th e nomin al se tting of
22. 2%.
In most cas es a setting of22.2% will be OK providing th at th •! true atm os ph e ric pressure is not too hi gh or too low .
Consult
th· ~ table below for these variations:
5. Replace t
he rear coYer. The Analyser is n ow re-c al ib ra te d.
High Pressures Low
Pre s sw-es
Pressure Value
Pre ss me
Value
·-
-·
·-
1013 mb 22.2 1013 mb 22.2
1018 mb 22.3 1008 mb 22.l
1023 mb 22.4 1003 mb 22.0
1028 mb 22.5
998m b 21.9
1033 mb 22.6 993 mb 21.8
1038 mb 22.7 988 mb 21.7
·-
1043 mb 22.8 983 mb 21.6