A. "Invisible traps" for frequent excessive benzene detection

In the catalytic reforming workshop of a petrochemical plant, when the operator patrolled with a portable benzene detector, it repeatedly showed that the concentration exceeded 25ppm (occupational exposure limit), but the re - test after ventilation was still on the high side. The investigation found that the sampling point was close to the waste oil barrel containing benzene, and the volatile benzene vapor adhered to the detector probe, resulting in a "false excess".

1.Hazard classification of benzene

Short - term exposure > 50ppm: dizziness, nausea, central nervous system depression
 Long - term exposure: It is a Class 1 carcinogen by the International Agency for Research on Cancer (IARC), increasing the risk of leukemia

2.Error - prone points in detection

Oil contamination on the probe can cause the response value to be 30% or more higher, and it needs to be wiped with absolute ethanol
When the temperature is > 35℃, the saturated vapor pressure of benzene rises, and the temperature compensation coefficient needs to be calibrated

3.Operation specifications

The patrol route should avoid the downwind direction within 10 meters of the material leakage point
Before the first use every day, calibrate the zero point with 10ppm benzene standard gas

B. Solution

MulitiRAE RAE - Sep Tube Cartridge benzene detection tube + RAE multi - gas detector

 1.Core features

Equipped with an oil - resistant coated probe to reduce the impact of oil adsorption, with a response recovery time < 30 seconds
Built - in temperature compensation algorithm, with an error < 5% in the range of - 20~54℃
Explosion - proof grade Ex ia II C T4, suitable for the explosion - proof environment of the catalytic workshop

2.Actual measurement effec

After using it in a petrochemical plant, the false alarm rate of benzene detection decreased from 25% to 3%