3. User guide
3.1 Indented use
The NOD is a portable tool designed for long-term detection of nitrous oxide. The user is provided
with indications of exposure and logs data for subsequent analysis.
When designing the NOD the assumption has been that the user wears the NOD as close to the face
as possible for an entire work shift. This is necessary for the average calculations of nitrous oxide
exposure and for the alarms to be relevant.
Further information can be found in section 6.
Clean the NOD with a regular cloth as needed.
3.2 Measurement Data
The unit can be set to comply with local regulations, and will trigger an alert if the concentration of
nitrous oxide exceeds the threshold limit values. Configuration of the NOD is made before delivery.
Exact measured value:
The nitrous oxide concentration is measured in parts per million (ppm) every minute, the NOD allows
for real-time continuous monitoring with a sensitivity down to 25 ppm. The average exposure is
calculated and recorded over a 15-minute period.
Indications of exposure:
-The short-term average for 15 minutes is set to 500 parts per million (ppm) to indicate exposure, if
the limit value is not otherwise specified. The short-term average value is calculated every 15 minutes
to trigger an alarm if the limit value is exceeded. When the limit value is exceeded, a pulsating sound
signal will be emitted for 3 seconds, and the diode will light up with a solid red light as an indication.
-The long-term average for 8 hours is set to 100 parts per million (ppm) to indicate long-term
exposure, if no other value is requested. The long-term average value is calculated every 4 hours to
trigger a pre-warning and an alarm if the limit value is exceeded.
When the limit value is exceeded, a pulsating sound signal will be emitted for 5 seconds, and the LED
will light up with a solid red light as an indication.
The Nitrous Oxide Detector is fitted with a filter that captures exhaled carbon dioxide (CO2) before
measuring the concentration of nitrous oxide, ensuring an accurate measurement. The filter needs to
be replaced before the start of each work shift.
In order to extract the data, you must first turn off the unit. Then, connect one end of the USB cable to
the USB/Charger Port on the Nitrous Oxide Detector and the other end to a USB port on your
computer.
3.3 Reading Data
Verify that the NOD is switched off. Using a USB cable, connect the NOD to the computer with an
internet connection and a web reader. Once the NOD is connected, turn the device on, the LED on
the NOD should be blue indicating that the NOD is connected to a computer.
Further instructions and tools can be found at: https://nod.medclair.com/
DU4000-M2 User Manual – Revision: A2
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