Signal conditioners amplify and condition weak signals generated by process sensors. They send signals long distances without being degraded by electrical noise. They are also used to drive useful devices such as indicators, alarms, controllers, computer interfaces and other process instrumentation.

AP4000 - AP9000 Series
The AP4000 to AP9000 Signal Conditioners are compact, electronic plug-in modules that take direct sensor inputs and signals and convert them in to useful high level signals. They operate directly from 120VAC power or 24VDC on some models.

The 4000 Series provides a complete line of interface and conditioning for temperature, pressure, flow, load and other process-sensing devices.

Four-Wire Transmitters
The 4000 Series are called "four-wire" transmitters since they operate from external line power (typically AC) -- two wires for output signal, two wires for operating power. Outputs are conventional DC process signals such as 4-20mA or 0-10V, and are fully compatible with all important process instrumentation equipment, including other Action Pak modules. When AC power is impractical or not available, most 4000 Series are available with a DC option that can be operated from a 24VDC power source.

Isolation
The practice of grounding remote sensors is usually advised to reduce noise pickup and protect equipment from being damaged by lightning or other high voltages. If both sensor and signal conditioner are grounded, it is possible to get an unwanted current, due to ground-to-ground potential differences, known as a ground loop. Ground loops degrade signal quality to the point of uselessness and can harm receiving equipment and personnel.

Isolation eliminates existing and potential ground loops, eliminates common mode voltage and checks power surges. Also, isolation simplifies the connection of loop elements by eliminating the need for special grounding systems.

Input Selection
Seven standard types of input are available to suit your process needs, other input types are available upon request.

• DC Voltage or Current
• Thermocouple
• RTD
• Strain-Gauge
• Potentiometer
• AC Voltage or Current
• Frequency

Three-Year & Lifetime Warranties
Action Paks which contain our Application Specific Integrated Circuit (ASIC) have seventy percent fewer internal connections for higher reliability and carry a lifetime warranty. Other Action Paks are backed by Action Instruments' exclusive three-year warranty.