UNISENSE Nitrous Oxide Sensors User Guide
- October 30, 2023
- UNISENSE
Table of Contents
UNISENSE Nitrous Oxide Sensors User Guide
Important! Test sensor upon receipt!
This sensor has been successfully tested prior to shipping. However, some sensors suffer from rough transportation. Therefore, it is important that you test the sensor upon arrival.
Replacement of defective sensors
Unisense will replace the sensor if it does not meet the specifications below, provided that:
-
A test is performed upon receipt without breaking the seal
(Note! No seal on MR-sensors for testing purposes) -
The complaint is given to Unisense within two weeks from receipt of the equipment.
Guaranteed lifetime
Unisense guarantees the nitrous oxide sensor a minimum lifetime of 2 months on condition of correct storage and use according to the manual.
Individual sensor calibration is Required
Our sensors are handmade and as the sensor signal relies on the exact geometry of the sensor tip (micrometer scale), some variation must be expected.
Signal amplification
Unisense nitrous oxide sensors should be connected to a Unisense amplifier such as a UniAmp series instrument or the Field Microsensor Multimeter
Standard nitrous oxide sensors are functioning correctly if (at Room temperature):
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The 90 % response time to changes in N2O is less than 20 seconds
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The 90 % response time for N2O-R should be less than 65 seconds
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The 90 % response time for N2O-MR and N2O-NP should be less than 45 seconds
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The zero signal is less than 30 % of the stabilized signal for 100 µM nitrous oxide in water and below 20 mV*
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The sensor signal in pA is converted to an instrument signal in mV. The default setting of this Pre-Amp range is 1 pA = 1 mV. However, this can be changed by the user (see the instrument manual).
Patent information
This product is covered by the following patents:
Patent issued in China: CN 104937405 A
Patent issued in USA: 9921178
Patent issued in Japan: JP6275744B2
Patent pending in several other jurisdictions.
Unisense A/S
[email protected]
www.unisense.com
Phone: +45 89 44 95 00
Fax: +45 89 44 95 49
1. Unpacking
- Remove the grey shock-absorbing plastic net and inspect the sensor visually. Leave the sensor in the protection tube for testing.
2. connect the sensor to the amplifier
- Set the polarization voltage to -1.3 V for pre-activation of the sensor.
- For Uniamp series instruments, adjust the polarization in the calibration window or in the Unisense Service in the Windows Notification Area.
- For Multimeter, Monometer, and Field Multimeter adjust the polarization on the instrument.
- For other ampliers, set the polarization manually to -1.3 V.
NOTE! Incorrect polarization may destroy the sensor
A typical decrease in sensor signal over time for a sensor that has just been plugged in.
3. Wait for the sensor to stabilize
- Wait for 30 minutes and adjust the polarization to -0.8 V.
- The signal will first fluctuate and then decrease over time for at least 2 hours. If possible, leave the sensor to stabilize overnight.
- Once the signal is stable, calibration can be performed.
4. Calibrate the sensor
- Use air saturated water as one calibration point. This is easily done using the CAL300 calibration chamber. The sensor may be dipped directly into the calibration chamber or the air saturated water may be injected into the protection tube using the calibration cap. A typical decrease in sensor signal over time for a sensor that has just been plugged in.
- CAL300 with microsensors and bubbling with air.
Use the Unisense N2O solution as the second calibration point. Inject the N2O solution into the calibration cap (incl. in calibration kit) and wait for the sensor to respond.
- For alternative calibration method, see the N2O Microsensor manual.
5. Approve the sensor
- Compare the sensor signals to the specications given on the previous page. If necessary, see Troubleshooting in the N2O Microsensor manual or contact support (see below).
Injecting calibration liquid into protection tube using the calibration cap.
6. Storage
- When not in use, store the sensor with the protection tube mounted at room temperature or in a fridge (approx. 4°C) for longer lifetime. If the sensor is used regularly, keep it polarized and connected to the amplier.
Useful tools
For support go to
www.unisense.com/support or
contact [email protected]
Get the full manuals for all
sensors, equipment & software
at www.unisense.com/manuals
Find SDS for Calibration Kit here
Version: May 2023