The SP-MGTP is the pumped instrument in the Senko portable range. The internal pump draws sample through a probe or a length of tubing, so the atmosphere inside a tank, a vault or a manhole can be characterized from outside it, before anyone commits to the space.
Why the pump matters
29 CFR 1910.146(d)(5)(i) requires the permit space to be tested to determine whether acceptable entry conditions exist before entry is authorized. A diffusion monitor can only report the air it is sitting in, so satisfying that requirement without entering the space needs a pump and a probe that reaches the space from outside.
The same section sets the order of the test at 1910.146(d)(5)(iii): "When testing for atmospheric hazards, test first for oxygen, then for combustible gases and vapors, and then for toxic gases and vapors." The reason is given in Appendix B to the standard. Most combustible gas sensors need oxygen to work, so a combustible reading taken in an oxygen deficient atmosphere cannot be trusted.
Channels
Configurations run to six channels. Beyond the standard four, the two that change what the instrument can do are:
PID, for volatile organic compounds. A photoionization detector sees solvent and fuel vapors that a catalytic LEL sensor reads as almost nothing at low concentration. If your hazard is residual product in a tank, a PID channel is the difference between a useful number and a flat zero.
Infrared carbon dioxide. Carbon dioxide is not combustible and does not show on an LEL sensor. It is heavier than air and it collects in low spaces. If you work in vaults, cellars, pits or anywhere near bulk CO2, this is the channel that sees it.
What a PID will not tell you
A PID reports a total VOC number, not a compound. It cannot tell benzene from toluene. Where benzene specifically is the regulated exposure, under 29 CFR 1910.1028, a total VOC reading is not a benzene measurement and should not be recorded as one. Benzene specific measurement uses a pre filter tube ahead of the PID.
Ordering
Select the configuration from the list. The SKU shown is the Senko part number. Probes, tubing, calibration gas and docking stations are ordered separately.
