PHYWE Cobra4 User manual

1
www.phywe.com, © All rights reserved 12634-00 / 0915
Operating instructions
Cobra4 Sensor-Unit Colorimeter 12634-00
PHYWE Systeme GmbH & Co. KG
Robert-Bosch-Breite 10
D–37079 Göttingen
Telefon [phone]
Fax [phone]
E-mail [email protected]
The unit complies
with the correspond-
in
g
EC
g
uidelines.
Fig. 1: 12634-00 Cobra4 Sensor-Unit Colorimeter
TABLE OF CONTENTS
1SAFETY INSTRUCTIONS
2PUPOSE AND CHARACTERISTICS
3FUNCTIONAL AND OPERATING ELEMENTS
4OPERATING INSTRUCTIONS
5HANDLING
6TECHNICAL DATA
7SCOPE OF SUPPLY
8ACCESSORIES
9WARRANTY
10 WASTE DISPOSAL
1 SAFETY INSTRUCTIONS
•Read the operating instructions thoroughly and com-
pletely prior to starting the unit. Please read also the op-
erating instructions of the measurement data recording
device that is used (Cobra4 Wireless-Link, USB-Link,
Mobile-Link, or Junior-Link). This is important for your
own protection and for avoiding damage to the unit.
•Only use the unit for its intended purpose.
•The unit is solely intended for use in dry rooms where
there is no risk of explosion.
•Protect the Cobra4 Sensor-Unit Colorimeter against dust,
moisture, and vapours. Clean the unit with a slightly
moist, lint-free cloth. Do not use any aggressive cleaning
agents or solvents.
•Ensure that no liquid can penetrate the housing. Other-
wise, the Cobra4 Sensor-Unit Colorimeter may be dam-
aged.
•When using the unit outdoors, ensure that no rain or
splash water can penetrate the housing.
•Do not open the unit.
•Connect the data output of the Cobra4 Sensor-Unit Col-
orimeter only to the intended measurement data re-
cording devices.
•Based on today's state of software development, it is im-
possible to guarantee that a product is completely free
from errors or defects.
This is why PHYWE Systeme GmbH & Co. KG does not
accept any liability for damage that results from the in-
stallation or use of this unit.
2 PUPOSE AND CHARACTERISTICS
The Cobra4 Sensor-Unit Colorimeter is used for measuring
the absorption or transmission of light. For this purpose, there
are four wavelengths: red: 650 nm, orange: 610 nm, green:
520 nm, and blue: 470 nm.

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Depending on the type of application, the Cobra4 Sensor-
Unit Colorimeter can be connected to one of the following
measurement data recording devices for the transfer of the
measurement data:
•Cobra4 Wireless-Link (12601-00) for the wireless data
transfer to a computer,
•Cobra4 USB-Link (12610-00) for the data transfer to a
computer via a USB cable,
•Cobra4 Junior-Link (12615-00) for the data transfer via
USB during student experiments,
•hand-held Cobra4 Mobile-Link (12620-10).
The front of the unit is equipped with an interface via which
the connection to the measurement data recording devices is
realised. Mechanically secure locking is ensured by way of
the lock knob and the corresponding hole.
3 FUNCTIONAL AND OPERATING ELEMENTS
3.1 Operating elements
The Cobra4 Sensor-Unit Colorimeter does not have any
manual operating elements. It is controlled by way of the
hand-held Cobra4 Mobile-Link or via a computer if it is con-
nected to a Cobra4 USB-Link, Cobra4 Wireless-Link, or Co-
bra4 Junior-Link, as soon as the connection between the
Sensor-Unit and one of the three measurement data re-
cording devices has been established.
3.2 Sensor interface
The measurement values can be read out of the Sensor-Unit
with a maximum rate of 10 measurement per second (10 Hz).
4 OPERATING INSTRUCTIONS
Combined with the Cobra4 Wireless-Link, Cobra4 USB-Link,
Cobra4 Junior-Link, and Cobra4 Mobile-Link, the Cobra4
Sensor-Unit Colorimeter fulfils the technical requirements that
are summarised in the current directives the of the European
Community. The unit must be used under the supervision of
an expert and in an electromagnetically controlled environ-
ment at research, teaching, and training facilities (schools,
universities, institutes, and laboratories).
This means that, in such an environment, radio transmission
devices, e.g. mobile phones, should not be used in the direct
vicinity of the unit. The connected cables must not be longer
than 2 m.
Electrostatic charges or similar electromagnetic phenomena
(HF, bursts, indirect lightning discharge, etc.) may affect the
unit so that it will not work within the specified data range.
The following measures reduce or eliminate the potential in-
terferences: avoid carpets; provide equipotential bonding;
perform the experiments on a conductive, earthed surface,
use shields and shielded cables. Do not use radiofrequency
transmitters (radio sets, mobile phones) in the direct vicinity
of the unit.
5 HANDLING
This section describes the start-up of the Cobra4 Sensor-Unit
Colorimeter and the recording of measurement data. Please
read this section thoroughly in order to avoid failures or oper-
ating errors.
5.1 Starting the Cobra4 Sensor-Unit Colorimeter
Software/device software update
Ensure that the current versions of the "measure" software
package and of the firmware of the Cobra4 module are in-
stalled.
Cost-free software update at:
www.phywe.com > Downloads > Software:
"measure" measurement software
PHYWE firmware
A cost-free update of the software is also possible via the
"measure" DVD.
Preparation
Connect the Cobra4 Sensor-Unit Colorimeter with one of the
four possible measurement data recording devices via the
15-pin snap-on connector. The Sensor-Unit is immediately
ready for operation since it is supplied with power via the
measurement data recording device. Please refer to the cor-
responding operating instructions for more information con-
cerning the operation and control of the measurement data
recording devices.
5.2 Performing an experiment
Positioning the cuvette
Insert the cuvette directly into the intended recess in the
housing of the Sensor-Unit Colorimeter. To do so, unscrew
and remove the cover (1) (Fig. 2). Then, the cuvette can be in-
serted. Screw the cover back on for the measurement (Fig. 3).
Fig. 2: Colorimeter without the cover
Fig. 3: Colorimeter with a cuvette
1

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www.phywe.com, © All rights reserved 12634-00 / 0915
Calibration
The sensor does not need to be calibrated, but for didactic
reasons and a higher level of accuracy, a calibration is rec-
ommended.
•Fill the cuvette with distilled water. Ensure that it
remains free from air bubbles.
•Insert the cuvette into the Sensor-Unit and close the
colorimeter cover.
•Adjust a transmission of 100 % for all of the wave-
lengths.
•Mobile Link: Menu Sensor Calibrate
•Measure: In the navigator, click the wavelength that
you would like to set to 100 %.
5.3 Recording of measurement data
Measurement:
For a conclusive measurement, it is important that the cu-
vette is clean, i.e. free from dust and fingerprints. The cu-
vettes can be cleaned rather well with kitchen paper (paper
towel).
•Fill your sample into the cuvette and ensure that it is
free from air bubbles.
•Prior to inserting the cuvette into the sensor, ensure
that it is clean on the outside and that there are no
liquid drops.
•The cuvette has two different types of sides: two
opposite sides are transparent, and the other two
are opaque. The clear sides should face the LEDs
or light-sensitive sensor. You can easily determine
the correct alignment by switching the sensor on. As
a result, you will see the lights of the LEDs.
•Screw the colorimeter cover back on and read off
the values.
The light of the four wavelengths will be emitted continuously
one after the other and the absorption will be measured.
The sensor has 4 channels (4 wavelengths) and 2 operating
modes:
% Transmission (% T): Part of the light that passes through
the sample.
Absorbance (Abs): The absorbance A is calculated based on
the intensity without the sample (I
0
) and based on the inten-
sity with the sample (I):
log



It is a unit-free measure.
6 TECHNICAL DATA
(typical data for 25 °C)
Operating temperature range: 5 to 40 °C
Rel. humidity: < 80 %
Measuring range: 4 wavelengths (LEDs):
red: 650 nm
orange: 610 nm
green: 520 nm
blue 470 nm
Transmission: 0…100 %
Resolution: 0.01 % T
Max. sampling rate: 10 Hz
Connector: Sub-D, 15-pin-type
Dimensions (L x W x H) 110 x 70 x 30 mm³
Weight: 100 g
7 SCOPE OF SUPPLY
The following items are included in the scope of supply:
•Cobra4 Sensor-Unit Colorimeter 12634-00
•Macro-cuvette, PS, 4 ml, 5 pieces
8 ACCESSORIES
Macro-cuvette, PS, 4 ml, 100 pieces 35663-10
9 WARRANTY
We guarantee the instrument supplied by us for a period of
24 months within the EU, or for 12 months outside of the EU.
Excepted from the guarantee are damages that result from
disregarding the Operating Instructions, from improper han-
dling of the instrument or from natural wear.
The manufacturer can only be held responsible for the func-
tion and technical safety characteristics of the instrument,
when maintenance, repairs and alterations to the instrument
are only carried out by the manufacturer or by personnel who
have been explicitly authorized by him to do so.
10 WASTE DISPOSAL
The packaging consists predominately of environmentally
compatible materials that can be passed on for disposal by
the local recycling service.
Should you no longer require this product,
do not dispose of it with the household re-
fuse.
Please return it to the address below for
proper waste disposal.
PHYWE Systeme GmbH & Co. KG
Customer Service
Robert-Bosch-Breite 10
D–37079 Göttingen
Phone [phone]
Fax [phone]