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February 2003 : DustAlarm® • SFD-2/SFI


Low Cost Smart Transmitter

Protect Blowers From Damage

Elburn, IL - Monitor Technologies' DustAlarm® Broken Bag Detector provides reliable and economical detection of filter failures in exhaust ducts of baghouses, cartridge collectors, and other types of dust collection equipment.

Employed in a variety of industries, the Alarm uses triboelectric technology, which provides uninterrupted dust monitoring, an alarm output indicating changes in filter conditions, and an adjustable sensitivity and time delay.

Its rugged NEMA 4 housing allows for optimal integral electronic protection and access to adjustments and LEDs.

Other features of the Alarm include a fail-safe operation that automatically changes to the alarm condition if the power applied to the unit should fail. An optional feature is a quick-disconnect assembly, which simplifies periodic cleaning.

Benefits of the Alarm include protecting blowers from damage, knowing when to replace dust collector filters, eliminating unscheduled downtime to replace filter bags, and reclaiming expensive dusts before they are released into the atmosphere.

Model SFD-2
Best Value
in Flow Detection

Elburn, IL - Utilizing excellent sensitivity and a non-intrusive housing design, Monitor Technologies' Solids Flow Detector (SFD-2) and Solids Flow Indicator (SFI) provide a signal indicating the flow/no-flow condition of solids and powders in gravity chutes, feeders and pneumatic pipelines.

The SFD-2 and SFI use low-power microwaves to sense motion. Microwaves are virtually unaffected by heat, humidity, ambient light, pressure, vacuum, high or low temperatures, or dust. This gives the SFD-2 and SFI with maximum effectiveness in industrial applications. Both units also carry Hazardous Location Approvals.

The non-contact/non-intrusive design ensures long-term reliability and elimination of process contamination. Intrusive probes might wear out, break off or inhibit material flow. The ability to sense through most non-metallic surfaces allows the SFD-2 and SFI to have a non-intrusive flush mounting.

The selection of either SFD-2 or the SFI is based upon the type of output required (relay or analog). With convenient remote electronics, the SFD-2 provides relay outputs. The SFI has a variable analog signal relative to the magnitude of flow. This provides more information for the user than the "on-off" flow detection of the SFD-2.

Spotlight: RF Capacitance Level Sensor
TrueCap Level SensorsTrueCap Light  
TrueCap® MK-2
Advanced RF Capacitance Level Probe

The TrueCap® Model MK-2 RF Capacitance point level probe is designed to provide a superior and stable sensitivity threshold making it suitable for a variety of powder / bulk solids and some liquid or slurry applications.

Advanced features of the Model MK-2 include:
> Automatic immunity to material build-up on the probe by its driven shield design
> Push-button calibration
> Enhanced temperature compensation
> Maximized reliability via smart sensing algorithms like “self-validating” fail-safe protection
> Visible status LED on ordinary location units
> Versatility through a variety of configuration options including: hazardous location version, split architecture design, quick-connect process connection, stub probe, cable extensions, solid extensions, Nylon® probes, Ryton® - equiv. probes, etc.

A practical application for the TrueCap would be to use this level sensor where a residual material build-up on a different sensor would cause a false material level indication.

Principle of Operation for the TrueCap RF Capacitance Level Probe:
The vessel wall and the active probe element establish an impedance reference between each other when exposed to air which has a dielectric constant of 1. When materials with a dielectric constant greater than 1 are in close proximity to the probe, the impedance of the sensing field between the sensor and the vessel wall will change. Once the amount of change exceeds a threshold that was electronically determined during the calibration process, an output relay will either be energized or de-energized depending upon the position of the fail-safe selector on the probe’s electronic circuit board. A change of as little as .5 pico-farad is all that is necessary for the probe to sense the presence of material.

Click here for more information on the TrueCap MK-2 Level Sensor or contact Monitor Technologies LLC at
Tel.: 800-766-6486 in the USA and
Tel.: 630-365-9403 worldwide.


>>Download TrueCap Product Bulletin #413

>>Click here to learn more about other Point Level Switches from Monitor Technologies


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