1
Introduction
The ODORATOR 2 is a handheld, portable, electronic GNSS based audit system used to
evaluate and record the odor
levels within a utility’s gas stream at actual test locations. Natural
gas (methane) and propane are two most common gases typically odorized and distributed.
Sample gas to be tested enters the ODORATOR 2 through the quick connect fitting at the gas
supply inlet port. Internally, the sample gas passes through an internal five-micron filter to the
input of a low-pressure regulator. It then passes from the output of the low-pressure regulator
to the flow metering valve. This valve, located on the top panel of the ODORATOR 2, is
controlled by the operator. After passing through the valve (when partially opened), the gas
enters a mass flow sensor. This is the heart of the ODORATOR 2. The mass flow sensor
responds to gas flow within the range of the flow metering valve. The signal from the mass flow
sensor is then converted to a digital signal, processed and fed to LCD display. Metered gas
from the mass flow sensor then passes to the mixing chamber where it is combined with fresh
air drawn in by a blower. The operator then sniffs the gas / air mixture at the exhaust port as
part of the test. If no odor is detected, the flow metering valve is incrementally opened, and the
exhaust port sniffed until odor is readily detectable at which time the operator presses the
READ switch to automatically record the corrected percent gas in air by volume, GNSS
location (GPS and/or GLONASS), test time & date and various instrument parameters. While
driving to the various test points in the distribution system the ODORATOR 2 may also
automatically record the GNSS location, date, time and various instrument parameters to be
able to show the actual breadcrumb trail used. The electronics and the speed of the blower are
calibrated so that the concentration of the gas / air sample at the exhaust port agrees with the
LCD reading at 20% of the Lower Explosive Level (LEL) or at a pre-determined point less than
20% of the LEL. For methane / natural gas and propane the LEL is typically 5.0% and 2.2%
respectively. All readings are automatically corrected for atmospheric pressure and
temperature via an embedded microcontroller and associated sensors. Depending on how
much flow metering valve is opened, the concentration of gas in air at the exhaust port will be
anywhere from zero up to approximately 2% for methane. An alarm and the display alert the
operator of instrument status, problems or high reading values.
INTRODUCTION
The ODORATOR 2 continuously monitors its health and operational status. Typical operational
checks include but are not limited to: blower speed, battery state-of-charge, GNSS, memory
card, communications buss, power supplies and calibration interval.
Included but not required for odor level testing is OdorSeer and OdorSeer Remote PC
software for managing the recorded data, mapping, report generation, instrument configuration
and remote data access. Connectivity interfaces include USB 2.0 and Bluetooth. Refer to the
OdorSeer / OdorSeer Remote manual for details.
A replaceable, rechargeable Li Ion battery pack is used to power the ODORATOR 2. An
external power supply is used to re-charge the battery pack. The ODORATOR 2 is designed
and intended to be used in accordance with the GPTC Guide For Gas Transmission And
Distribution Piping Systems (49 CFR) 192.625 Subpart L dated 10-1-13, the ASTM Standard
D 6273
– 08 and NFPA 58 for performing odor threshold level and relative odor intensity tests.
Supply gas must be high quality natural gas (methane) or propane. Blended or mixed gases as
sometimes found during peak shaving cannot be tested using the ODORATOR 2.
