OxyGuard Handy Polaris TGP User manual

OxyGuard Handy Polaris TGP
Instrutions for use

GENERAL
OxyGuard Handy Polaris TGP is a hand-held meter with built-in datalogger. It
measures the Total dissolved Gas Pressure, the oxygen (DO) partial pressure and
the temperature. The instrument calculates the pressure of other dissolved gases
from the total pressure and DO partial pressure. It can operate in three modes:
A) As a standard Polaris dissolved oxygen and temperature meter.
B) As a TGP meter that shows pressures as “percent saturation” values with
relation to water that is completely saturated with air. These are automa-
tically compensated for changes in the atmospheric pressure.
C) As a TGP meter that shows pressures as volume percentages relative to air at
the actual barometric pressure.
When measuring in air-saturated fresh water at 24°C the following
will be shown:
A) “Show Oxygen” mode:
100% SAT (O2); 8.40 mg/l (O2); 24.0 °C (temp.)
B) “Show TGP % Sat” mode:
100% SAT (O2); 100% TGP (total); 100% RES (rest; other gases)
C) “Show TGP % Vol” mode:
21% O2; 100% TGP (total); 79% RES (rest; other gases)
Messages on the display and menu functions make the Handy TGP easy to use. If
a menu is displayed, you can always go to the measurement display by pressing
"ESC" several times. To turn it on or off hold the on/off button ( ) depressed
for 3 seconds. TGP measurements take some time (20 or more minutes), so make
sure that the probe can be fixed in place in the water whilst the measurement is
made. We recommend that you fix the probe in place and leave it for 20 minutes
before you switch on and make the measurement.
Immerse the probe about 30 cm under the water surface. There should be some
movement in the water; 5–10 cm/sec is enough. Gas diffusion through water is
extremely slow, so movement helps the probe achieve gas pressure equilibrium
with the water and thus improves response time. Wait until the reading is steady
before noting it or storing it.
After use, rinse the probe in clean water and wipe the meter dry if it is wet.

Press an arrow button to select which parameter is shown in large figures. Press
"OK" to go from the measurement display to the menus. The arrow buttons can
then be used to make a selection and the "OK" button to confirm or go to the next
level. "ESC" is used to move back. If an error occurs, a warning will blink in the
display. More information is shown in the status list.
The residual gas pressure is obtained by subtracting the oxygen partial pressure
from the total pressure. If wanted the residual value can be compensated for
dissolved CO2 in the water and for the water vapour pressure at the instrument.
A carbon dioxide content of 20 mg/l results in a reduction in the measured TGP
of 1.4%.
Compensation for water vapour pressure can be made because the %sat values are
corrected for changes in barometric pressure sensed by a pressure sensor in the
instrument, where the water vapour pressure can be low. In the water, the water
vapour partial pressure corresponds to 100% humi-
dity. The default value for water vapour compensation assumes a relative humidi-
ty at the instrument of 80%. This results in a reduction in the measured TGP in the
water of 0.4%.
The probe is calibrated in fresh air. The calibration procedure, which is automatic,
calibrates the oxygen sensor and aligns the gas pressure sensor in the probe with
the barometric pressure sensor in the instrument.
MENU
From measurement use “OK” and the arrow buttons to reach the desired function.
The options are:
1) Calibrate
2) Start log or stop log (depending on present setting)
3) Show Oxygen
4) Show TGP %Sat
5) Show TGP %Vol
6) Setup
7) Show Log
8) Transfer to PC
9) Status list (only if there is an error)

1) Calibrate
Accurate measurements need accurate calibration, which in turn needs stable
conditions. Polaris TGP checks and only permits calibration if conditions are
stable. The sensitivity of this check can be changed - see "Setup – Calib. Preci-
sion". The “Field” setting is recommended.
A good way of checking calibration is to do so in the morning before taking the
Polaris into use. If you have stored it in its pouch in a place where the temperature
is moderate and stable, and leave the probe in the pouch when you turn it on and
check, conditions for the probe should be very stable!
Turn the Polaris on and observe the display. The following values are acceptable:
“Show oxygen”: 100.5% +/- 1%
“Show TGP %Sat”: 100% +/- 1%
“Show TGP %Vol”: 100% +/- 1%
If calibration is needed select "Calibrate" and press "OK" to start. Progress is
shown on the display. When "Calibration done" is shown press "OK" to measure.
If “Calibration error - unstable conditions” appears check that the “field” calibra-
tion precision is chosen and try again.
2) Start log
Use this menu function to start or stop logging. When viewing measurements
logging can also be started or stopped by holding “OK” or “ESC” respectively
depressed for 3 seconds.
3) Show Oxygen
Select this to make the instrument act as a standard Polaris 2 DO and temperature
meter.
4) Show TGP %Sat
Select this to make the instrument show partial pressure measurements as percent-
ages related to the actual atmospheric pressure, where a 100% value is the partial
pressure obtained when the water is saturated with air. Three values are shown,
%TGP, %02 and %RES:
%TGP is the total dissolved gas pressure

%O2 is the oxygen (partial) % sat value, which is the same %sat value as given by
a standard OxyGuard Polaris DO meter.
%RES is the residual gas (partial) % sat value. If the CO2 compensation is set to 0
mg/l, the CO2 partial pressure will be included in the residual pressure.
5) Show TGP %Vol
If you select this the instrument will show 20.9% O2, 79.1% RES and 100% TGP
when measuring in water that is 100% saturated with air.
6) Setup
This has 6 sub-menus:
a) User Interface
b) Compensation
c) Log Setup
d) Date & Time Menu
e) Calib Precision
f) Information
a) User Interface:
Language: The options depend on the language version.
Temperature Units: You can choose between °C and °F.
Display format % sat: You can choose with or without tenths.
Auto shutdown: The default of 2 minutes is recommended.
Light intensity: “Low” ensure longest battery lifetime.
b) Compensation:
You can set compensation for Salinity, the CO2 content of the water and the
relative humidity found in the air around the instrument when clalibrationg.
If you set the humidity to “0” then humidity compensation is disabled.
c) Log Setup
“Log mode”: lets you choose one-shot or interval logging.
Use “Log interval” to set the interval time for interval logging.

Use “Log Values” to select what should be logged. The options are “Barometer”,
“Rest gases”, “oxygen mg/l” and “oxygen %Vol”. Press “OK” and choose “Off or
On” to select.
“Max Log ID” sets the number of groups of logs the memory is divided between.
Store all measurements made the same place (both one-shot and interval) Under
the same ”Log ID”. Each measurement has specific date and time information.
“Full log handling” lets you choose between over-writing (recycle) or stopping
when the memory is full.
“Erase Log” lets you do just that.
“Log Status” shows the present setting of the datalogger.
d) Date and Time Menu
Dette menupunkt har tre underpunkter:
Set Date and Time
Set Date Format
Show Date and Time
e) Calib precision
Here you can choose between
“Field” (recommended, factory setting)
“Normal”
“High”
If conditions are stable "Field" can give just as accurate calibration as "Normal" or
"High". “Normal” ensures very precise measurements, and ”High” is the most
sensitive. “High” needs very stable conditions indeed.
f) Information
This shows the software version and serial numbers of probe and instrument.
7) Show Log:
“Graph” will show the logged data as graphs
“Table” will show data as tables
You will be asked for the memory block ID number you want to see.
Choose “0” to see all ID’s.

8) Transfer to PC
An OxyGuard Polaris Link is used to connect to a PC. Fit the link to the Handy
TGP. Plug the USB connector of the link into the PC. Select “Transfer to PC” on
the Polaris TGP, then start the program on the PC and select "Receive log" on the
PC. Data will be transferred. Load the data into an Excel spreadsheet for further
treatment.
9) Status List:
This only appears if there has been an error. Use ”OK” to see a list, select
an error and press “OK” again to see details. Use “ESC” to go back.
MAINTENANCE:
Keep the probe clean, rinse it after use. It is not advisable to leave it in the water
for long periods of time because this will permit the growth of deposits on it. The
probe can be cleaned in soapy water. Use a very soft brush if necessary. Replace
the bobbin if needed.
Keep the instrument itself dry. It can tolerate being dropped into the water, but
should be wiped dry afterwards. If you drop a warm Polaris into cold water
condensation might form inside it, so if this has happened take the instrument to a
dry place and open the back plate. Inspect it carefully and make sure that it is
completely dry inside before closing it again.
Change the battery when “Low Batt” appears in the display. Do not wait until the
battery has run down completely. The Polaris TGP uses more power than a Polaris
for DO alone, so we recommend that rechargeable batteries are used and
exchanged regularly, for example every 14 days.
Battery Exchange
Use the tool to unscrew the rear plate. The battery can then easily be exchanged.
Take care not to pull the battery wires. Take care not to disturb the ribbon cable.
Make sure that you tighten the rear plate well, and do NOT get the inside of the
meter wet!

Sensor Element Replacement
Take the probe up, rinse it well and dry excess water from it. Unscrew the protec-
tor. Carefully unplug the sensor element from the top part, ensuring that the
connection stud comes out of the top part. Make sure that the hole to the sensor is
clean. Plug in a new element and screw the protector into place. Take care not to
damage the stud or tube.
Protector and retainer
H08XPR
TGP Sensor Element
H08XSE

DO Sensor Renovation
Do NOT do this unless a message in the display tells you so. Remove the bobbin
as above and follow the instructions in the drawings to renovate the DO sensor.
Take care to make sure that you only turn the cap. If the cap is difficult to unscrew
grip the top part just above the cap with a tool (as shown below, fig. 1).
Do NOT screw the cap very tightly. Note that the new membrane must not
wrinkle (see below, stage 6). If this happens try again with a new membrane and
O-ring. Wait a few hours before calibrating, since the probe will take a little
time to settle down. Check the calibration during the next few days.
NB: For health and safety purposes treat the electrolyte as concentrated salt water.

Specifications:
Dimensions, meter: 98 mm diameter, hight 36 mm
Dimensions, meter: Dia. 58 mm, height 110 mm + cable gland
Cable Length: Standard 3 m. other on request
Operating Conditions: Probe: -5 to +45° C, meter -20 to +60°C.
Encapsulation (meter): Short-term immersion proof to 5m depth.
Display: Graphical LCD display. Variable backlight.
Parameters measured: Oxygen partial pressure, total dissolved gas
pressure, temperature at probe.
Oxygen Probe Type: Galvanic cell, self polarizing, self temperature
compensating.
Self-check of: Probe function, meter function, cable, battery
Useful battery life: 35 days with 20 measurements per day (2
minutes “on” time per measurement)
Accessories included: Storage pouch, DO probe membranes with
o-rings & electrolyte, cathode cleaning pad.
Parametre displayed:
A) “Show Oxygen” mode:
In this mode the Handy TGP displays:
DO in mg/l, range 0-60.0 ppm (mg/l)
DO in % sat, range 0-600% saturation
Accuracy depends on calibration accuracy. Typically better than +/- 1% of
measured value +/- 1 digit within the standard range.
Repeatability typically better than +/- 0.5% of measured value.
DO measurement automatically compensated for temperature and barome-
tric pressure. Manual salinity compensation between 0-59 salinity.
Temperature, range -5 to +45° C, accuracy +/- 0.2°C.