ONGUARD 4000
The Purafil OnGuard 4000 (OG4) Atmospheric Corrosion Monitorindicates the level of corrosion before severe damage occurs, preventing costly downtime and maintenance repairs. Reactivity monitoring is an accu- rate and reliable method of evaluating the quality of air, characterizing the room environment, and evaluating the effectiveness of chemical filters. The OG4’s copper and silver sensors measure the rate of corrosion in real-time. An internal data logger stores the results to be accessed through the internet or directly transmit to a process con-trol system. Ideal for control rooms, server rooms, motor control centers, rack rooms, or other areas where corrosion is a concern, the OG4 prompts preventive action before
serious problems develop.

Benefits
•Indicates the level of corrosion before severe
damage occurs
• Prevents costly repairs and production downtime
•Tracks peaks and trends to determine the level of
corrosion
• Easy access to data and graphs
• Readings correspond to ISA Standard 71.04-2013
•Low maintenance: Sensors need replacement at 4000
Angstroms of cumulative corrosion growth
• RoHS compliant

Features
•Measures corrosion, temperature, and relative humidity
on a continuous basis
•Direct interface provided by the backlit LCD
and keypad
• Remote power from network cable (PoE)
•4-20mA connection with existing facility management
systems or distributed control systems (DCS)
• AA battery-powered for remote or inaccessible areas
• Provides incremental and cumulative corrosion data
• Long service life
• Accurate within ± 0.5-1% of full span

Principle of Operation
The OG4 comes with two quartz crystal microbalance
(QCM) sensors, one that is plated with copper and anoth-
er with silver. The QCM is used to measure the corrosive
film that results from the environment. This highly sensitive
method of measurement will indicate contaminant levels
at or less than one part per billion (1 ppb). The corrosion
film thickness is measured and recorded in Angstroms (Å).
This measurement corresponds directly to ISA Standard
S71.04-2013.

ONGUARD 4000
The Purafil OnGuard 4000 (OG4) Atmospheric Corrosion Monitorindicates the level of corrosion before severe damage occurs, preventing costly downtime and maintenance repairs. Reactivity monitoring is an accu- rate and reliable method of evaluating the quality of air, characterizing the room environment, and evaluating the effectiveness of chemical filters. The OG4’s copper and silver sensors measure the rate of corrosion in real-time. An internal data logger stores the results to be accessed through the internet or directly transmit to a process con-trol system. Ideal for control rooms, server rooms, motor control centers, rack rooms, or other areas where corrosion is a concern, the OG4 prompts preventive action before
serious problems develop.

Benefits
•Indicates the level of corrosion before severe
damage occurs
• Prevents costly repairs and production downtime
•Tracks peaks and trends to determine the level of
corrosion
• Easy access to data and graphs
• Readings correspond to ISA Standard 71.04-2013
•Low maintenance: Sensors need replacement at 4000
Angstroms of cumulative corrosion growth
• RoHS compliant

Features
•Measures corrosion, temperature, and relative humidity
on a continuous basis
•Direct interface provided by the backlit LCD
and keypad
• Remote power from network cable (PoE)
•4-20mA connection with existing facility management
systems or distributed control systems (DCS)
• AA battery-powered for remote or inaccessible areas
• Provides incremental and cumulative corrosion data
• Long service life
• Accurate within ± 0.5-1% of full span

Principle of Operation
The OG4 comes with two quartz crystal microbalance
(QCM) sensors, one that is plated with copper and anoth-
er with silver. The QCM is used to measure the corrosive
film that results from the environment. This highly sensitive
method of measurement will indicate contaminant levels
at or less than one part per billion (1 ppb). The corrosion
film thickness is measured and recorded in Angstroms (Å).
This measurement corresponds directly to ISA Standard
S71.04-2013.