D e t e c t i o n
NEO Photo-ionization detector
User Manual
D e t e c t i o n
20
Set Pump Stall Threshold
The Pump Stall Threshold is the current-draw setting for a blocked pump alarm.
The default setting is 500. The actual, real-time pump current draw is displayed in
the upper right corner. Briefly block the inlet probe with a finger and to observe
the rise in pump current value. Set the stall threshold about 50-100 units above
the unblocked pump reading, but lower than the blocked pump reading. Press
the Up or Mode key to increase or decrease each digit’s value, and the Right or
Left key to move the cursor. Then move the cursor to ‘√’ and press Up to save and
exit. Set a different pump stall threshold for each pump speed.
3-Point Calibration
Normally a 2-point calibration gives adequate linearity in PID response, but a
3-point calibration (Zero, Span 1 and Span 2) can be enabled for more accuracy,
particularly in the high concentration range above about 500 ppm where
response is less linear. Use the Right key to enter 3-Point Cal, then Up or Mode to
scroll to On or Off, Right to select, and Left to save and exit.
Below is the list of default 1st and 2nd Span points when using isobutylene for calibration. These settings
can be changed in the Calibration menu.
Rolling Graph
If the Rolling Graph function is enabled, the display in basic User Mode shows the instantaneous
reading together with a real-time plot of immediate past readings in a 2-minute window. Enable
the rolling graph as with any other list selection menu.
Real Time Data
Real time data output is available on some NEO models via a USB cable and/ or wirelessly via Bluetooth
Low Energy using an Android App. Please contact WatchGas for more information.
NEO Model
Span 1
Span 2
MP181
100 ppm
1000 ppm
MP182
100 ppm
5000 ppm
MP184
10 ppm
1000 ppm
MP185
10 ppm
1000 ppm
MP186
5 ppm (benzene)
N/A
