Table of Contents
Advertisement
Quick Links
Advertisement
Table of Contents
Summary of Contents for UNISENSE N2O-50
- Page 1 NITROUS OXIDE SENSOR USER MANUAL...
- Page 2 ITROUS OXIDE SENSOR MANUAL Copyright © 2024 · Unisense A/S Version January 2024...
- Page 3 NITROUS OXIDE SENSOR MANUAL UNISENSE A/S...
-
Page 4: Table Of Contents
TABLE OF CONTENTS WARRANTY AND LIABILITY........... 5 CONGRATULATIONS WITH YOUR NEW PRODUCT! . -
Page 5: Warranty And Liability
The warranty does not include repair or replacement necessitated by accident, neglect, misuse, unauthorized repair, or modification of the product. In no event will Unisense A/S be liable for any direct, indirect, consequential or incidental damages, including lost profits, or for any claim by any third party, arising out of the use, the results of use, or the inability to use this product. -
Page 6: Congratulations With Your New Product
• The seal is still intact. • The sensors are returned to Unisense for inspection within two weeks. • The sensors are correctly packed for return to Unisense, in accordance with the note included in the sensor box. -
Page 7: Overview
O concentrations above their working range. LR: Low Range; SR: Standard Range; IR:Intermediate Range; HR: High Range. The Unisense nitrous oxide microsensor is a miniaturized Clark-type sensor with an internal reference and a guard cathode. In addition, the sensor is equipped with an oxygen front guard, which prevents oxygen from interfering with the nitrous oxide measurements. - Page 8 high-sensitivity picoammeter and the cathode is polarized against the internal reference. Driven by the external partial pressure, nitrous oxide from the environment will penetrate through the sensor tip membrane and be reduced at the metal cathode surface. The picoammeter converts the resulting reduction current to a signal.
-
Page 9: Getting Started
GETTING STARTED WARNING NPACKING AND CONNECTING A NEW SENSOR Do not remove When receiving a new microsensor, first remove the the seal and shock-absorbing grey plastic net. Then secure the sensor protective in a safe position (e.g. micromanipulator or calibration plastic tube chamber) before connecting it to the measuring meter. -
Page 10: Pre-Activation Procedure
For directions on adjusting the polarization, please consult the relevant instrument manual. ACTIVATION PROCEDURE NOTE 1. Secure the nitrous oxide sensor with its tip immersed The software in nitrous oxide free water. (It does not harm the sensor converts the to be in air instead, but pre-activation, polarization, and pA signal into calibration might as well be made with the same set-up). -
Page 11: Calibration Principles
The membrane permeability of nitrous oxide microsensors changes with time, so a change in signal of up to 50% may occur over months. ALIBRATION It is recommended to use the Unisense N O Sensor Calibration Kit for calibrating the N O sensors (https://www.unisense.com/... -
Page 12: Alternative Calibration
(nitrous oxide partial pressure 0.003679 atm × solubility 27,05 × 10-3 mol/liter/atm. = 100 mol/liter, see Table 2). For a Unisense 300 ml calibration chamber CAL300, 5 minutes of bubbling at a rate of 5 L per minute is sufficient time to achieve 99% of the concentration. - Page 13 Calculate the appropriate mixture from the solubilities given in Table 2. Alternatively, use the N2O calculator in the Unisense software (Tools - N2O Calculator) or the Unit Converter on the Unisense website: Click “Knowledge” - “Unit Converter”.
-
Page 14: Approval Of New Sensor
Do not stir bubbles into the water and do not mix by bubbling, as this will flush nitrous oxide from the water. A magnetic stirrer is also not recommended as a mixing tool because it can introduce electrical noise to the signal. The nitrous oxide in the water will slowly escape to the atmosphere and the concentration can only be considered constant for a few minutes. -
Page 15: Measurements
The signal of the microsensor is in the 10 to 10 ampere range. Although both the Unisense picoammeter and the Unisense nitrous oxide microsensors are quite resistant to electrical noise from the environment, electrical fields may interfere with the sensor signal. -
Page 16: Interference
during measurements. NTERFERENCE Exposure to high concentrations of sulfide should be avoided as it can affect the sensitivity of the nitrous oxide microsensor. Nitric Oxide (NO) is interfering the N O sensor signal. CO2 in mM concentrations may affect the zero signal of the sensor. On suspicion of sensor damage, repeat calibration and consult ‘Trouble-shooting’. -
Page 17: Advanced Use Of The N O Sensor
ADVANCED USE OF THE N O SENSOR Unisense can construct nitrous oxide sensors for customer requested applications at an additional cost. Unisense provides several options for customizations and adaptions (e.g. tip size, response time, pressure tolerance, and stirring sensitivity) making accurate measurements possible for even more applications. -
Page 18: Storage And Maintenance
STORAGE AND MAINTENANCE Always store the sensor in the protective plastic tube used for shipping. The nitrous oxide microsensor can be stored with the tip exposed to water or air. The sensor can be stored dry at room temperature (15-30°C) or in the fridge (approx. 4°C) which may give a longer lifetime. -
Page 19: References
REFERENCES • Andersen, K., T. Kjaer, and N. P. Revsbech. 2001. An oxygen insensitive microsensor for nitrous oxide. Sensors and Actuators B-Chemical. 81(1):42-48. • Elberling, B., Christiansen, H.H. and Hansen, B.U. 2010. High nitrous oxide production from thawing permafrost. Nature geoscience 3:332-335. -
Page 20: Troubleshooting
Possible cause Air bubble in the narrow parts of the sensor. Solution Shake the sensor as you would shake an old school mercury thermometer. See video guide here: unisense.com/ video-guides/ Problem A slow response Possible cause Insoluble compounds deposited at the sensor tip Rinse with 96% ethanol, rinse with 0.01M HCl and rinse with... - Page 21 Contamination of the cathode surface (e.g. by sulfide) or loss of the cathode material due to excessive vibration. Replace the microsensor. Solution If you encounter other problems and need scientific/technical assistance, please contact sales@unisense.com for online support (we will answer you within one workday) 21 21...
-
Page 22: Appendix: Equilibrium N O Concentrations
17.73 15.33 14.01 Source: Weiss, R.F; Price, B. A.: Marine, Chemistry, 1980, 8, 347-359 For conversion between units go to the Unit Converter on Unisense website: unisense.com/unit-converter/# The Unisense software has a built-in calculator, giving the solubility of N2O at a given combination of temperature and salinity (“Tools -... - Page 23 · sales@unisense.com...