pyroscience FireStingO2 User Manual

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FireStingO2

FIBER-OPTIC OXYGEN & TEMPERATURE METER

USER MANUAL

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Document Version 3.081
Refers to Pyro Oxygen Logger Software version >3.3

The FireStingO2 is manufactured by

PyroScience GmbH

Hubertusstr. 35
52064 Aachen
Germany

Phone [phone]
Fax [phone]
Email [e-mail]
Internet www.pyroscience.com

Registered: Aachen HRB 17329, Germany

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TABLE OF CONTENT

1 OVERVIEW .............................................................................. 5

2 SAFETY GUIDELINES ............................................................... 7

3 INTRODUCTION TO THE FIRESTING METER ........................... 10

4 SOFTWARE INSTALLATION ................................................... 12

5 OPTICAL OXYGEN & TEMPERATURE SENSORS ..................... 13

5.1 OVERVIEW OF SENSOR TYPES .................................................... 13

5.2 CONNECTING THE SENSORS ....................................................... 14

5.3 CLEANING AND MAINTENANCE OF THE SENSORS........................... 15

6 THE SOFTWARE "PYRO OXYGEN LOGGER" ........................... 17

6.1 FIRESTING SETTINGS ................................................................ 18

6.1.1 Channel Tab: Optical Oxygen Sensors ................................ 19

6.1.2 Channel Tab: Optical Temperature Sensors ........................ 24

6.1.3 Temperature Tab ............................................................... 24

6.1.4 Options Tab ....................................................................... 26

6.2 MAIN WINDOW ........................................................................ 28

6.2.1 Chart Recorder .................................................................. 29

6.2.2 Warnings ........................................................................... 32

6.2.3 Measurement and Logging ................................................. 33

6.2.4 Raw Data Window .............................................................. 37

6.3 OVERVIEW PANEL .................................................................... 40

6.4 DATA FILE PANEL ..................................................................... 41

7 SENSOR CALIBRATION ......................................................... 42

7.1 OPTICAL OXYGEN SENSOR CALIBRATION ..................................... 43

7.1.1 Calibration Mode: Factory .................................................. 45

7.1.2 Calibration Mode: 1-Point in Ambient Air ............................ 46

7.1.3 Calibration Mode: 1-Point in Water or Humid Air ................. 49

7.1.4 Calibration Mode: 2-Point in Ambient Air ............................ 51

7.1.5 Calibration Mode: 2-Point in Water or Humid Air ................. 55

7.1.6 Calibration Mode: Custom Mode ........................................ 59

7.2 OPTICAL TEMPERATURE SENSOR CALIBRATION ............................ 65

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8 OXYGEN CALIBRATION STANDARDS ....................................68

8.1 THE AIR CALIBRATION STANDARD .............................................. 68

8.1.1 Ambient Air ....................................................................... 70

8.1.2 Water-Vapor Saturated Air ................................................. 71

8.1.3 Air Saturated Water ............................................................ 71

8.2 THE 0% OXYGEN STANDARD ..................................................... 72

8.2.1 Water Mixed with a Strong Reductant ................................ 72

8.2.2 Water Flushed with Nitrogen Gas ........................................ 73

8.2.3 Nitrogen Gas ...................................................................... 73

9 CALIBRATION OF CONTACTLESS SENSORS .......................... 74

9.1 CALIBRATION PROCEDURE ......................................................... 74

9.2 MANUAL BACKGROUND COMPENSATION .................................... 75

10 TEMPERATURE MEASUREMENT ............................................ 77

10.1 EXTERNAL (PT100) TEMPERATURE SENSORS ................................ 77

10.2 INTERNAL TEMPERATURE SENSOR ............................................... 77

10.3 OPTICAL TEMPERATURE SENSORS .............................................. 78

10.4 AUTOMATIC TEMPERATURE COMPENSATION ................................ 78

11 ANALOG OUTPUT AND AUTO-MODE .................................... 81

11.1 ANALOG OUTPUT .................................................................... 81

11.2 AUTO-MODE ........................................................................... 84

11.3 ADVANCED AUTO-MODE .......................................................... 86

12 APPENDIX ............................................................................ 88

12.1 SPECIFICATIONS OF THE FIRESTINGO2 ......................................... 88

12.2 EXTENSION PORT X1 ................................................................ 90

12.2.1 Connector X1 (Power, Digital Interface, Analog In) .......... 90

12.2.2 Connector X2 (Analog Output) ....................................... 95

12.3 TROUBLESHOOTING ................................................................. 96

12.4 OXYGEN MEASURING PRINCIPLE ................................................ 97

12.5 OPERATING SEVERAL FIRESTINGO2 IN PARALLEL ........................... 99

12.6 DEFINITION OF OXYGEN UNITS ................................................. 100

12.7 TABLE OF OXYGEN SOLUBILITY ................................................ 102

12.8 EXPLANATION OF THE SENSOR CODE ........................................ 104

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1 Overview

The compact USB-powered fiber-optic meter FireStingO2 with 1,
2, or 4 channels unifies several innovative technological
improvements making it the new standard of oxygen sensing with
fiber-optical oxygen sensors (optodes). The FireStingO2 utilizes a
measuring principle based on red light excitation and lifetime
detection in the near infrared using luminescent oxygen indicators
(REDFLASH technology, see Appendix 12.4). It is a multifunctional
oxygen meter working

• for oxygen measurements in water as well as in gas phases,

• with fiber-based sensors comprising several size classes

like microsensors, minisensors, or robust probes,

• with contactless sensors for oxygen and temperature like

sensor spots, flow-through cells or respiration vials, and

• with full range and trace oxygen sensors,

• with optical temperature minisensors.

The FireStingO2 has integrated atmospheric pressure and
humidity sensors for a precise and easy sensor calibration, but also
for automatic pressure compensation of the oxygen
measurements. Furthermore, the FireStingO2 offers 4 analog
outputs and a built-in temperature port for an external PT100
temperature probe for automatic temperature compensation of
the oxygen measurement. If independent temperature
compensation for all oxygen channels is needed, a USB-powered
temperature extension module TeX4 can be easily fixed below the

FireStingO2 meter with a smart docking mechanism. Or the new

optical temperature sensors can be connected to any channel of
the FireStingO2 meter. By placing the same sensor type for
oxygen and temperature into the sample, true temperature
compensation of the oxygen measurements can be achieved.

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The user-friendly Pyro Oxygen Logger software allows operation
of several FireStingO2 meters in parallel as a scalable multi­channel system.

Along with the FireStingO2 we offer turnkey motorized setups for
measurements of depth-profiles in semi-solid environmental
samples and along micro-gradients at high temporal and spatial
resolution. And several customized OEM solutions are available for
application in industry and underwater.

More information concerning our products can be found at

www.pyroscience.com

or contact us at [e-mail].

Your PyroScience Team

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2 Safety Guidelines

The FireStingO2 is a laboratory instrument to be used with fiber­optic oxygen and temperature sensors (optodes) from

PyroScience. In order to guarantee an optimal performance of the
FireStingO2, please follow these operation instructions and safety

guidelines.

If any problems or damage evolve, disconnect the instrument
immediately, mark it to prevent any further use and consult

PyroScience for repair or maintenance service. The FireStingO2

should not be manipulated or opened by unauthorized persons,
only by PyroScience or persons advised directly from PyroScience.

Please note that opening the housing will void the warranty. There
are no serviceable parts inside the device.

The FireStingO2 and sensors should be kept and stored outside the
reach of children in a secure place under dry and clean conditions
at room temperature, avoiding moisture, dust, corrosive
conditions and heating of the instrument. This device and the
sensors are not intended for medical, military or other safety­relevant areas. They must not be used for applications in humans;
not for in vivo examination on humans, not for human-diagnostic
or therapeutic purposes. The sensors must not be brought in direct
contact with foods intended for consumption by humans.

The FireStingO2 should be used in the laboratory by qualified
personal only, following the operation instructions and safety
guidelines of this manual. Please follow the appropriate laws and
guidelines for safety, like EEC directives for protective labor
legislation, national protective labor legislation, safety regulations
for accident prevention and safety data-sheets from
manufacturers of chemicals used during the measurements.

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Calibration and application of the sensors, data acquisition, data
processing and data publication is on the user's authority.

When used in the field, the environmental conditions (like high
humidity, dust, exposure to direct solar radiation) may cause
damage or interference of the FireStingO2, which is on the user's
authority.

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Before using the FireStingO2 and its sensors, read carefully the
instructions and user manual for the oxygen meter FireStingO2.

In case of problems or damage, disconnect the instrument and
mark it to prevent any further use! Consult PyroScience for
advice! There are no serviceable parts inside the device. Please
note that opening the housing will void the warranty!

The FireStingO2 is not watertight, is sensitive to corrosive
conditions and to changes in temperature causing
condensation. Avoid any condition (e.g. direct sun light) causing
a heating of the device above 50°C (122°F) or below 0°C (32°F).
Avoid any elevated humidity causing condensing conditions.

Handle the sensors with care especially after removal of the
protective cap! Prevent mechanical stress to the fragile sensing
tip! Avoid strong bending of the fiber cable! Prevent injuries
with needle-type sensors!

Calibration and application of the sensors is on the user’s
authority, as well as data acquisition, treatment and
publication!

The sensors and the oxygen meter FireStingO2 are not intended
for medical, diagnostic, therapeutic, or military purposes or any
other safety-critical applications. The sensors must not be used
for applications in humans and must not be brought in direct
contact with foods intended for consumption by humans.

The FireStingO2 and sensors should be used in the laboratory by
qualified personnel only, following the user instructions and the
safety guidelines of the manual, as well as the appropriate laws
and guidelines for safety in the laboratory!

Keep the sensors and the oxygen meter FireStingO2 out of
reach of children!

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3 Introduction to the FireSting Meter

The FireStingO2 is an optical oxygen meter that is compatible with
a broad range of optical oxygen and temperature sensors from

PyroScience:

 microsensors and minisensors (retractable needle-type,

fixed needle-type, or bare fiber),

 robust probes and
 contactless sensors (sensor spots, respiration vials, flow-

through cells)

Most oxygen sensors are available in versions for the full range (0­50% O2, max. range 0-100% O2) and for the trace range (0-10%
O2). The optical detection technology is based on the oxygen­sensitive REDFLASH indicators which use red light excitation and
lifetime detection in the near infrared (see Appendix 12.4 for more
details).

The FireStingO2 is a compact USB-powered fiber-optic oxygen
meter with 1, 2 or 4 channels for oxygen and temperature
measurements in the laboratory. The optical temperature sensors
can be used for true automatic temperature compensation of the
oxygen measurements. Additionally, one external PT100
temperature probe can be connected for calibration of the optical
temperature sensors and for automatic temperature
compensation of the oxygen measurements. The integrated
sensors for atmospheric pressure (mbar) and relative humidity (%
RH) of the ambient air enable a precise and easy sensor calibration,
as well as automatic pressure compensation of the oxygen
measurements.

The FireStingO2 is operated via a Micro-USB connection to a PC /
tablet with a Windows operation system. The included logging
software Pyro Oxygen Logger provides comfortable calibration
and logging functionality.

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The FireStingO2 is a laboratory instrument. Use in the field is on
the user´s authority and then it is recommended to protect the

FireStingO2 from heating, moisture and corrosion.

The FireStingO2 comes with 1, 2, or 4 channels (connectors 1 to 4)
for up to 4 fiber-optic sensors and one connector (T) for an external
PT100 temperature probe.

The Micro-USB connector on the left side panel provides the
energy supply and the data exchange with the PC. Right-hand side
of it, a connector X1 for power and digital interface (7-pins) and a
connector X2 for analog output (5 pins) is located. The holes
function as air inlet for the internal temperature, pressure and
humidity sensors. Avoid covering these holes to ensure free air
circulation towards the internal sensors.

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4 Software Installation

IMPORTANT: Do not connect the FireStingO2 to your PC before
the Pyro Oxygen Logger software has been installed. The software
will install automatically the appropriate USB-drivers.

System requirements:

 PC with Windows 7 / 8 / 10 (but not Windows RT) and min.

700 MB free disk space

Installation steps:

 download the installer package for the newest version of

the Pyro Oxygen Logger software from the PyroScience
homepage: www.pyro-science.com/downloads.html

 unzip and start the installer and follow the instructions
 connect the FireStingO2 with the Micro-USB cable to the

computer. The red logo will flash shortly indicating the
correct startup of the FireStingO2 meter.

After successful installation, a new program group "Pyro Oxygen
Logger" is added to the start menu, and a short-cut named
"Oxygen Logger" can be found on the desktop.

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5 Optical Oxygen & Temperature Sensors

For an overview of available optical oxygen and temperature
sensor types, please see http://www.pyro-science.com/products.html.

5.1 Overview of Sensor Types

Sensor

Type

Fiber-Based

Available

Versions

Analyte

Application

Robust

Probes

OXROB3

O2

stirred water, gas

& semi-solid

samples

OXROB10

O2

Retractable

Needle-Type

OXR50

O2

water, gas &

semi-solid

samples -

for profiling &

small volumes,

puncturing septa

OXR230

O2

OXR430

O2

TPR430

Temp.

Fixed

Needle-Type

OXF50

O2

gas & water -

gas-tight housing,

sensor insertion

through a port

OXF1100

O2

TPF1100

Temp.

OXF500-PT

O2

gas -

gas-tight housing,

puncturing septa,

packing material

OXF900-PT

O2

Bare Fiber

Sensors

OXB50

O2

water, gas &

semi-solid

samples -

integration into

custom housings

OXB230

O2

OXB430

O2

Solvent-

Resistant

Probes

OXSOLV

O2

approved polar

and non-polar

solvents

OXSOLV-

PTS

O2

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Sensor

Type

Contactless

Available

Versions

Analyte

Application

Nanoprobes

OXNANO

O2

aqueous solutions

- microfluidics,
cultures,

enzymatic react.

Sensor Spots

OXSP5

O2

water & gas* ­measurements in
closed containers

with transparent

window

TPSP5*

Temp.

Respiration

Vials

OXVIAL4

O2

water & gas -

measurements in

closed vials, of

respiration / net

photosynthesis

rates

OXVIAL20

TOVIAL4

Temp. &

O2

TOVIAL20

Flow-

Through

Cells

OXFTC

O2

water & gas*

pumped through

the cell

OXFTC2

TPFTC*

Temp.

TPFTC2*

TOFTC2

Temp. &

O2

* Gas measurements only in combination with corresponding contactless

O2 sensor for true temperature compensation

For details on the different sensor types, please see their
respective websites.

5.2 Connecting the Sensors

The fiber-optic oxygen and temperature sensors, including needle­type and bare fiber micro- and minisensors, robust probes, as well
as optical fibers needed for read-out of contactless sensors (sensor

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spots, flow-through cells, respiration vials) are connected to the
ST-connectors of the FireStingO2 (1 to 4) with a male fiber plug.

First, remove the black caps from the plug of the sensor / fiber.
Then remove the red caps from the sensor ports at the FireStingO2
(the red caps should be put on again if the FireStingO2 is not in use
anymore to protect the optics). Insert the male fiber plug of the
sensor cable into the ST-port (female fiber connector) of the

FireStingO2 and turn the bayonet coupling gently clockwise until

the plug is locked firmly.

5.3 Cleaning and Maintenance of the Sensors

The oxygen sensors can be sterilized with ethylene oxide (EtO) and
can be cleaned with peroxide (3% H2O2), soap solution or ethanol
(do not use bleach!). They can be applied in gas phases, aqueous
solutions and in ethanol, methanol and isopropanol (robust probes:
only short-term application in diluted ethanol, methanol or
isopropanol). Other organic solvents and gaseous chlorine (Cl2)
induce interferences with the sensor reading. No cross-sensitivity
is found for pH 1-14, CO2, CH4, H2S and any ionic species.

For application in organic solvents, a special solvent-resistant
oxygen probe (item no. OXSOLV or OXSOLV-PTS) is available.

The optical temperature sensors can be applied in water / aqueous
samples and gas. If required, soap solution or 3% H2O2 can be
used for cleaning, as specified on the sensor website.

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A signal drift of the sensor can indicate photo-bleaching of the
oxygen-sensitive REDFLASH indicator or the temperature
sensitive THERMOGREEN/THERMOBLUE indicator depending on
the ambient light intensity, as well as the intensity of the excitation
light and the sample frequency. This can necessitate a new
calibration of the sensor and possibly also a re-adjustment of the
Sensor Settings (LED intensity; see also chapter 6.1). In case of
sensor spots, this could require a re-positioning of the optical fiber
on the sensor spot and a subsequent new calibration. If the signal
intensity is getting too low, as indicated by the horizontal indicator

bar in the Pyro Oxygen Logger software and by the respective

warning (see chapter 6.2), the sensor needs to be replaced.

A reasonable optical sensor shows signal intensities well above 50.

After finalization of the measurements, the sensor tip of the
needle-type and bare fiber sensors, as well as the robust probes
should be rinsed carefully with demineralized water, let dry and
put on the protective cap / tubing for storage in a dry, dark and
secure place at room temperature. For all sensors and fibers, put
the black caps on the plug of the fiber to prevent that light is
entering the fiber possibly causing photo-bleaching of the
indicator.

In case of retractable sensors and application in seawater / aqueous
samples with dissolved salts, the sensor has to be cleaned
thoroughly with demineralized water to prevent salt crystallization
in the needle which can cause breaking of the sensor tip. After
drying, retract the sensor tip into the needle and put on the
protective cap onto the needle to protect the sensor tip and to
avoid injuries.

Store the sensor in a dry, dark and secure place at room
temperature.

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6 The Software "Pyro Oxygen Logger"

This chapter describes all functions of the Pyro Oxygen Logger
software excluding the calibration. Refer to the chapters 7-9 for a
detailed description of the calibration procedure of optical oxygen
and temperature sensors.

If the Pyro Oxygen Logger software is opened for the first time, the
FireSting Settings window opens automatically:

Activate each connected sensor in the respective channel tab of
the Settings window, corresponding to the channel number at the

FireStingO2 meter (see chapter 3). Enter the Sensor Code and all

relevant parameters (Units, Measuring Mode, Conditions in the
Sample) into each channel tab before calibration and

measurements, as described in detail in chapter 6.1.

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6.1 FireSting Settings

Each channel (1-4) of the connected FireStingO2 meter has its own
tab (channel 1-4) in the FireSting Settings window.

For all optical sensors, enter first the sensor code of each
connected optical sensor into the field Sensor Code in the
corresponding channel panel of the Settings window. It includes
information for optimal sensor settings and for calibration. The
first letter of the sensor code defines the sensor type. A detailed
explanation of the sensor code is given in chapter 12.8.

The channels can be activated independently by clicking on the
button Activate. Activation is indicated by a change from dark to
light green of the arrow in the button.

A text describing the connected sensor type appears on the right­hand side of this button after the Sensor Code (see label on
sensor) has been entered. This description will be shown in the
description display of the main window (see chapter 6.2) and also
in the data file (see chapter 6.4).

Depending on the optical sensor type and analyte, there are
different parameters which need to be adjusted in the respective
channel tab of the Settings window (see chapter 6.1.1 for oxygen
and 6.1.2 for optical temperature sensors).

If the same sensor type (with the same Sensor Code) is connected
to all channels (e.g. 4 sensor spots from the same packaging unit),
the settings adjusted in the active channel tab can be pasted to all
other channels by clicking on Copy these Settings to all other
channels.

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After the first start, the dialog window FireSting Settings opens
automatically. For later adjustments, it can be opened by clicking
on the Settings button in the Main Window.

Settings can only be adjusted if data logging is not active (see
chapter 6.2.3).

6.1.1 Channel Tab: Optical Oxygen Sensors

Enter the Sensor Code of each connected oxygen sensor (see label
on sensor) and define for each channel (1) the Sensor Settings
(Measuring Mode), (2) the environmental Conditions in the
Sample under investigation and (3) the oxygen Units for the
measurements.

(1) Sensor Settings

The Sensor Settings can be adjusted
in a Basic or an Advanced mode.
Ensure that the correct sensor code
attached to the sensor has been
entered in the field Sensor Code.

The first-time user is advised to work with the Basic Sensor
Settings.

Basic Settings

For contactless sensors (sensor spots, flow-through cells,
respiration vials, nanoprobes; sensor type: S, W, T, P) and for
robust probes (sensor type: X, U), the Fiber Length (m) of the
connected optical fiber (e.g. SPFIB) or of the connected robust
probe (e.g. OXROB10) must be entered additionally (for interested
users: the entered fiber length is used for automatic background
compensation; refer to chapter 9.2 for more details).

The Measuring Mode can be adjusted gradually between low drift
(1) and low noise (5) of the sensor signal by moving the arrow with

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the mouse along the scale, thereby changing the measuring time.
An intermediate mode (3) is default.

NOTE: Ensure that the correct sensor code has been entered.

Advanced Settings (for advanced users/applications only)

If Advanced Sensor Settings are
chosen, more complex setting controls
get visible. Ensure that the correct
Sensor Code has been entered.

The Advanced Sensor Settings
comprise the LED Intensity for
excitation of the REDFLASH indicator (in %) and the Amplification
of the sensor signal. As a rule of thumb, the LED Intensity should
be 10-30% for microsensors, minisensors and robust probes, but
can be increased up to 100% for contactless sensors (sensor spots,
flow-through cells, respiration vials). The Amplification is typically
200x or 400x and should not be changed. Note, that varying the
LED Intensity and the Amplification has direct influence on the
signal intensity and therefore on the signal-to-noise-ratio!

The Oxygen Measuring Time (default: 10 ms) defines the
integration time for the acquisition of a single data point. Shorter
measuring times provide low long-term drift, whereby longer
measuring times assure less noise. The maximum value is 250 ms.

For background compensation of robust probes (sensor type: X),
the Fiber Length (m) of the connected robust probe must be
entered.

For background compensation of contactless sensors (sensor
spots, flow-through cells, respiration vials, nanoprobes; sensor
type: S, W, T, P), the Fiber Length (m) of the connected optical
fiber must be entered. Alternatively, it is possible to select Manual
Background Compensation, which is described in detail in chapter

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9.2. Finally, the background compensation can be completely de­activated by selecting No Background Compensation (not
recommended in general).

NOTE: Recommended is to enter the Fiber Length (m) for
background compensation. The alternative options Manual
Background Compensation or No Background Compensation
are only intended for advanced users/applications.

If using Advanced Sensor Settings, a 2-Point calibration of the
oxygen sensor must be performed. Later re-adjustments in the

Advanced Settings require new sensor calibration.

(2) Conditions in the Sample

The next step is the determination of the
Conditions in the Sample during the
measurements. For this, select the

SAMPLE: Water (Dissolved Oxygen) or

Gas Phase.

TEMPERATURE compensation: by

- an External Temperature Sensor
(PT100) connected to the temperature
port of the FireStingO2,

- a Fixed Temperature (needs to be
determined, adjusted manually and kept
constant), or

- an Optical Temperature sensor
connected to a Channel at the FireStingO2
meter (its respective channel number
needs to be entered here).

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For Gas measurements, temperature could be measured in
principal also by the Internal Temperature Sensor of the

FireStingO2, but this is NOT recommended!

If External Temperature Sensor, Internal Temperature Sensor
(in a Gas Phase) or Optical Temperature Channel is selected,
automatic compensation of temperature changes on the
respective oxygen sensor readings is activated (see chapter 10.3).
The Compensation Temperature will be displayed in the
corresponding channel panel of the main window (see chapter 6.2).

NOTE:

If an External or Optical Temperature Sensor was selected, it has
to be fixed in the sample container/calibration standard in which
oxygen measurements/calibration with automatic temperature
compensation will be performed.

If internal temperature sensor was selected (not recommended),
ensure the same temperature conditions for the gas sample and
the FireStingO2.

If a Fixed Temperature was selected, the temperature in the
sample/calibration standard must be measured, adjusted and kept
constant (needs to be controlled)! Ensure constant and defined
conditions!

PRESSURE compensation: by

- the Internal Pressure Sensor (recommended as default) or

- at Fixed Pressure (mbar) (recommended for applications with
different pressure conditions experienced by the oxygen sensor
and FireStingO2 meter). The actual pressure at the sensor position
needs to be determined with e.g. a barometer and adjusted
manually (default: 1013 mbar).

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If the actual atmospheric pressure cannot be determined on site, it
is also possible to enter the

- Elevation (m) above sea level. For this click on Elevation and
enter the actual elevation in meters. This procedure will only
calculate the average atmospheric pressure for this elevation;
therefore this option is less precise than measuring the actual
atmospheric pressure.

If Internal Pressure Sensor is selected, the oxygen measurements
are automatically compensated for pressure changes e.g. caused
by weather changes.

SALINITY: The Salinity (g/L) of the environmental sample is only

relevant if a concentration unit for dissolved oxygen DO
measurements was selected (e.g. mg/L or µmol/L). The sample
salinity needs to be measured and entered, e.g. in case of saline
water. For measurements in gas samples this value has no
relevance (and is not active).

(3) Units

The oxygen unit can be selected for each channel by the selector
Units. The selectable units include raw value (default), % air
saturation, % O2, mL/L, µmol/L, mg/L (ppm), hPa (mbar), mmHg
(Torr), dphi and µg/L (ppb).

For measurements in a Gas Phase only the units raw value, % O2,
hPa (mbar), mmHg (Torr) and dphi can be selected, whereas for
measurements of dissolved oxygen in a Water sample (DO) all
units except % O2 can be selected. For detailed information please
refer to chapter 12.6.

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6.1.2 Channel Tab: Optical Temperature Sensors

To enter the Settings for an
optical temperature sensor
connected to a FireStingO2
channel, open the respective
channel tab in the FireSting
Settings window of the Oxygen

Logger software.

Enter the Sensor Code of the
connected optical temperature
sensor (see label on sensor).

The Unit for the temperature readings is °C.

The Measuring Mode for the optical temperature sensor can be
adjusted gradually between low drift (1) and low noise (5) of the
sensor signal by moving the arrow with the mouse along the scale,
thereby changing the measuring time. An intermediate mode (4) is
default.

Ensure that the sensor code of a sensor connected to a specific
channel (e.g. 2) of the FireStingO2 meter is entered in the same
channel panel (e.g. 2) in the window FireSting Settings.

6.1.3 Temperature Tab

An External Temperature
Sensor (PT100) connected to
the temperature port T of the

FireStingO2 meter (see

chapter 3) and the Internal
Temperature Sensor (within
instrument) can be activated

in the FireSting Settings tab
Temperature.

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Both temperature sensors can be activated independently even if
Fixed Temperature or Optical Temperature Sensor was selected
for temperature compensation of all connected oxygen sensors (in
this case the oxygen measurements are not affected by these
temperature sensor measurements). The measured temperature is
then displayed in the Overview panel (see chapter 6.3) of the main
window and saved into the data file (see chapter 6.4).

After activation of an external PT100 / internal temperature sensor
in an oxygen sensor channel tab of the Settings (see 6.1.1), the
temperature measured by these temperature sensors is then
displayed in the respective channel tab and the Overview tab of
the Main Window in units of degree Celsius (y-axis on the right­hand side) and is saved into the data file (see chapter 6.4).

The Temperature Measuring Time (only multiples of 100 ms
possible) of the External Temperature Sensor (PT100) can be
optionally (a) increased in order to reduce the noise of the
temperature measurement or (b) decreased in order to achieve
higher sampling rates.

A Manual Offset of the External Temperature Sensor (PT100)
might be entered for a 1-point calibration of the temperature
sensor (default: 0). It is recommended to check the reading of the
external temperature PT100 probe periodically in stirred water/
water bath/incubator of known temperature at steady state. This is
especially important if a concentration unit (like µmol/L or mg/L)
was selected for the oxygen measurements in the Settings.

Changing the temperature offset will lead to a loss of the oxygen
sensor calibration.

To check for a temperature offset it is also possible to prepare a
water-ice-mixture giving 0°C, where at least 50 mm of the PT100
temperature probe tip is submerged. Wait for steady state, read
the measured temperature, and enter it as a negative

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Temperature Offset. Then perform a new calibration of the
connected optical sensor.

Please note that each FireStingO2 meter provides only a single
port for an external PT100 temperature probe. For Automatic
Temperature Compensation (see chapter 6.1.1) of >1 oxygen
sensor with an external PT100 temperature probe, all oxygen
sensors with automatic temperature compensation have to
measure at the same temperature condition. Alternatively, optical
temperature sensors can be connected to optical sensor channels
or the temperature extension module TeX4 can be coupled to the

FireStingO2, offering 4 ports for PT100 temperature probes.

6.1.4 Options Tab

In the Settings tab Options, several internal sensors and an Analog
In can be activated. The Internal Pressure Sensor and the Internal
Humidity Sensor inside the FireStingO2 meter can be

independently activated by clicking on the respective buttons and
are displayed in the Overview panel of the main window and saved
into the data file. If the Internal Pressure Sensor of the

FireStingO2 was activated in one of the oxygen channel tabs (see

6.1.1), it is automatically activated in the Options panel.

It is possible to designate a specific
name to the connected FireStingO2 in

Device Name e.g. “Water Container
Nr.42”. This device name is then

indicated in the top line of the main
window. This option is especially useful
if several FireStingO2 devices are
operated in parallel in order to
distinguish the opened logger windows.

The activation of the Analog In button allows to read in a voltage
signal at the extension port, e.g. from third-party sensors. The

27

measuring range is 0-2.5V and the display and output of the signal
is in mV. For details refer to chapter 11.

The maximum number of data points kept in the graphs can be
changed by the selector Max. Data Points in Graphs (default:

10800). A change of the number will clear the graphs and high
values (>>10000) might decrease the maximum sample rate.

The FireStingO2 offers four analog outputs (0-2.5V) at the
extension port which can be configured by pressing the Analog

Output button. For details refer to chapter 11.

Only for advanced users:

The USB communication
speed can be adjusted e.g. for

improving the maximum
sampling rate (default: 57600).

Activation of the button Enable High-Speed Sampling will enable
the adjustment of a Sample Interval <0.25 s in the main window
(and disable Max. Data Points in Graph). Details on request!

The Advanced Auto-Mode button allows advanced configuration
options for the Auto-Mode. For details refer to chapter 11.

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6.2 Main Window

After adjusting the Settings for all connected sensors after start of
the Oxygen Logger software, the following main window is shown:

The four panels Channel 1-4 correspond to the fiber-optic sensors
connected to the ports 1-4 at the FireStingO2 (see chapter 3). For
the 1- or 2-channel version of the FireStingO2, only the respective
panels will be visible.

The default sensor readings show uncalibrated sensor readings (in
raw value). For oxygen sensors this gives only qualitative
information of the actual oxygen level.

After activation of the respective channels in the Settings (see
chapter 6.1), the sensor readings of each channel are displayed in
its corresponding panel in a numeric display (D) and in a chart
recorder (C) in the chosen unit (UD).

The description of the sensor type, as defined in the Settings by
the Sensor Code, is shown in the description display (DD). The

Signal intensity (SI) of each oxygen sensor is shown in its channel

tab as horizontal indicator bar underneath the numeric display (D).

If a sensor was not yet calibrated or its Settings were changed, a

warning Not Calibrated is displayed in the Warning Display.

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6.2.1 Chart Recorder

The color and appearance of each graph can be changed by
clicking on the color-control (CC), opening a pop-up menu. With

Common Plots, Color, Line Style, Line Width, Interpolation, and
Point Style the chart appearance can be changed. Clicking on the

small rectangular button allows hiding / showing the respective
graph.

The visible time frame of the chart recorder (C) can be changed by
moving the bar along the scroll bar (SCB). Switching off the
Autoscroll button will allow inspection of older data which are not
visible anymore in the time frame, e.g. during longtime
measurements.

The display of the data in the charts can be changed by different
chart tools arranged underneath the chart recorder. The button
with the magnifying glass offers different zoom options. After
clicking the button with the hand, the user can click onto the chart
and move the whole area while keeping the mouse button pressed.

30

Note that placing the mouse on many elements of the window will
show a short description ("tool tip"). By clicking on the right mouse
button and selecting "Description and Tip" a more detailed
description might be available additionally.

Clear Graph

The button Clear Graph offers the options to clear only the graph
of one channel (Clear Single Graph), or to Clear Graphs of all
Channels & Zero Time Scale (i.e. the graphs in all other panels will
be also cleared). Note, that this will not affect the saved data in the
data file.

Adjust Scales

The unit of the x-axis (Time) can be changed with the selector
Time Scale (using the arrows or clicking onto the field). The time
scale can be displayed in Seconds (s), Minutes (min), Hours (h),
Relative Time (HH:MM:SS), Absolute Time (HH:MM:SS), Absolute
Time & Date and in Data Points.

For a channel tab with connected optical oxygen sensor and
external temperature PT100 sensor, the y-axes can be Oxygen
(left) and Temperature (right). For a channel tab with connected
optical temperature sensor the y-axis is optical Temperature (left;
opt. Temp.).