User's Manual
24 || G7 EXO TECHNICAL USER MANUAL
7.4 LEL SENSOR PRECAUTIONS
For safety reasons EXO must be operated and serviced by qualied
personnel only. Read and understand the information below before
operating or servicing.
SAFETY WARNING: O-scale (overlimit) readings may indicate an
explosive concentration.
SAFETY WARNING: Calibrations must only be performed in areas free of
ammable gases.
Blackline’s LEL sensors can be calibrated with the following settings:
No known gases desensitize or contaminate Blackline’s LEL-MPS and
LEL-IR sensors. These two sensors do not cause any electromagnetic
interference (EMI), and are not negatively aected by EMI, such as radio
transmissions, of up to 8W.
Like any gas sensor, be sure to understand potential explosive hazards
and choose the appropriate sensor technology based on these hazards.
Blackline Safety supports three dierent LEL sensor technologies:
1. Molecular Property Spectrometer (LEL-MPS)
2. Non-Dispersive Infra-Red (LEL-IR),
3. Catalytic-bead pellistor (LEL-P)
Molecular Property Spectrometer (LEL-MPS)
This sensor is not intended for inert enviroments. Enviroments with
oxygen (O) levels below 18% will negatively impact this sensor’s
accuracy and Blackline does not recommend using it when oxygen
levels are below 10%.
When bump testing or calibrating this sensor, apply a gas mixture
containing at least 18% oxygen (O). Less oxygen than this may
negatively impact the sensor’s readings. If a gas mixture with less than
18% oxygen is applied during a bump test or calibration, restart EXO to
auto zero the sensor.
This sensor can be calibrated two ways, default calibration and full calibration.
1. The default calibration process will validate and ensure accuracy
without adjusting the LEL-MPS sensor’s readings. Unlike traditional
sensors, this sensor is factory calibrated for optimal accuracy. We
recommend using the factory calibration for the lifetime of the sensor.
2. Advanced users can perform a full calibration with a span
adjustment. A full calibration may negatively impact the accuracy of
other gases. EXO can be congured to run a full calibration on this
sensor in Blackline Live.
Non-Dispersive Infra-Red (LEL-IR)
This sensor is able to function in inert environments without oxygen.
This sensor does not detect Hydrogen (H) or Acetylene (CH).
Catalytic-bead pellistor (LEL-P)
Any rapid up-scale reading followed by declining or erratic reading may
indicate a gas concentration beyond upper scale limit which may be
hazardous. Blackline does not oer this LEL sensor anymore.
7.5 PID TARGET GASES
What are target gases?
Photo-ionization detector (PID) sensors can be used to detect a large
range of gases called VOCs (volatile organic compounds). The PID
sensor’s target gas refers to the specic gas your device is attempting
to detect. EXO’s readings will be adjusted based on the target gas it is
congured to detect.
NOTE: Although PID sensors target a specic VOC gas, readings can still
be aected by the presence of non-targeted gases. Consult your safety
supervisor or industrial hygienist when preparing to use a PID sensor.
How do I set EXO’s target gas?
EXO’s PID sensor’s target gas is set from the conguration prole in
Blackline Live. Under the photoionization detector section of the gas
sensor settings card, you can choose an existing target gas or set a
custom target gas.
Where do I see which target gas EXO is detecting?
The target gas EXO is congured to use can be seen in two places:
On startup
In the gas options menu, Gas options > View gas info > VOC target
In both places EXO’s screen will display the name of the target gas as
well as its correction factor.
Gas Calibration
concentration
(%vol)
Calibration
concentration
(%LEL)
Balance
Methane (CH) 2.5% 50% ±2% Standard quad-
gas mixture