Parameter

Equipment

Calibration

Source of Calibration Standards

Equipment Maintenance

Equipment Decontamination

Volatile organic compounds (VOCs)

Photoionization detector (PID)

Daily according to manufacturer's instructions with ambient air (considered 0 mg/L) and isobutylene gas (100 mg/L).

Commercially available, premixed, in cylinders.

Avoid prolonged use in humid environments; keep probe away from dirt or free water; recharge battery.

Replace instrument filter; clean lamp.

VOCs

OVA

Daily, and every 2-3 hours during use, methane in air.

Scott specialty gases.

Charge batteries; keep probe out of liquids.

Not applicable.

Explosive gases

Combustible gas indicator

Daily with known gas and concentration; daily testing in known explosive environment (gas tank) and zero adjustment in clean environment.

Commercially available, battery.

Keep inlet away from dirt or free liquids; recharge battery.

Not applicable.

pH

Hydac pH, temperature, and conductivity meter

Daily with known pH buffer solutions.

Commercially available.

Keep instrument face dry.  Replace battery when necessary.

Squirt pH probe with water after every use.

Conductivity

Hydac pH, temperature, and conductivity meter

Daily with solution of known conductance.

Commercially available.

Keep instrument face dry.  Replace battery when necessary.

Clean sample cup with water and paper towel after every use.

Water level in well

Water level indicator

Check against steel tape.

Commercially available.

Replace battery when necessary.

Squirt probe with water after every use.