the Signal Conditioning Specialists
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dc Input Conditioning

dc Input Products

Select products that measure dc input parameters and produce a standard process signal output or an alarm state.

  • TOC
    • Top
    • dc Input Conditioning
    • Process Signals
    • 4-20mA Input
    • 4-20mA Input Powered
    • dc A Input
    • dc mA/V mA and V Input
    • dc mV Input
    • Footer

Find a Product Input ⇒ Function ⇒ Output

  • 4-20mA
    • 4-20mA, Select Function
    • Alarm
      • 4-20mA Alarm, Select Output
      • 4-20mA 4-Wire
        • 4-20mA Alarm 4-20mA 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 4-Wire
        • 4-20mA Alarm dc mA/V 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Relay
        • 4-20mA Alarm Relay, Select Product
        • DTA137 Dual Trip Alarm
        • STA138 Single Trip Alarm
        • TRA173 Triple Trip Alarm
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Select Output
    • Isolator
      • 4-20mA Isolator, Select Output
      • 4-20mA 2-Wire
        • 4-20mA Isolator 4-20mA 2-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • 4-20mA Isolator 4-20mA 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • 4-20mA Isolator dc mA/V 3-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • 4-20mA Isolator dc mA/V 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • 4-20mA Isolator Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • High Drive
        • 4-20mA Isolator High Drive, Select Product
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • Pulse/ Frequency
        • 4-20mA Isolator Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • PWM157 Analog To PWM
        • Select Product
      • Relay
        • 4-20mA Isolator Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Resistance
        • 4-20mA Isolator Resistance, Select Product
        • ATR167 Analog To Resistance
        • ATP168 Analog to Potentiometer
        • Select Product
      • Select Output
    • Transmitter
      • 4-20mA Transmitter, Select Output
      • 4-20mA 2-Wire
        • 4-20mA Transmitter 4-20mA 2-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • 4-20mA Transmitter 4-20mA 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • 4-20mA Transmitter dc mA/V 3-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • 4-20mA Transmitter dc mA/V 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • 4-20mA Transmitter Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • BSC133 Bipolar Signal Converter
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • High Drive
        • 4-20mA Transmitter High Drive, Select Product
        • BSC133 Bipolar Signal Converter
        • BSI134 Bipolar Signal Isolator
        • PD121 Power Driver
        • PD122 Power Driver
        • Select Product
      • Pulse/ Frequency
        • 4-20mA Transmitter Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • PWM157 Analog To PWM
        • Select Product
      • Relay
        • 4-20mA Transmitter Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Resistance
        • 4-20mA Transmitter Resistance, Select Product
        • ATR167 Analog To Resistance
        • ATP168 Analog to Potentiometer
        • Select Product
      • Select Output
    • Select Function
  • 4-20mA Input Powered
    • 4-20mA Input Powered, Select Function
    • Isolator
      • 4-20mA Input Powered Isolator, Select Output
      • 4-20mA Input Powered
        • 4-20mA Input Powered Isolator 4-20mA Input Powered, Select Product
        • SPI232 Signal Powered Isolator
        • Select Product
      • Select Output
    • Select Function
  • dc A
    • dc A, Select Function
    • ac Transducer
      • dc A ac Transducer, Select Output
      • 4-20mA 4-Wire
        • dc A ac Transducer 4-20mA 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • dc mA/V 4-Wire
        • dc A ac Transducer dc mA/V 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • Select Output
    • Alarm
      • dc A Alarm, Select Output
      • Relay
        • dc A Alarm Relay, Select Product
        • DCA218 dc Current Alarm
        • Select Product
      • Select Output
    • Isolator
      • dc A Isolator, Select Output
      • 4-20mA 4-Wire
        • dc A Isolator 4-20mA 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • dc mA/V 4-Wire
        • dc A Isolator dc mA/V 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • Pulse/ Frequency
        • dc A Isolator Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • Select Product
      • Select Output
    • Transmitter
      • dc A Transmitter, Select Output
      • 4-20mA 4-Wire
        • dc A Transmitter 4-20mA 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • dc mA/V 4-Wire
        • dc A Transmitter dc mA/V 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • DCT247 Dc Current Transducer
        • Select Product
      • Pulse/ Frequency
        • dc A Transmitter Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • Select Product
      • Select Output
    • Select Function
  • dc mA/V
    • dc mA/V, Select Function
    • ac Transducer
      • dc mA/V ac Transducer, Select Output
      • 4-20mA 4-Wire
        • dc mA/V ac Transducer 4-20mA 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • Select Product
      • dc mA/V 4-Wire
        • dc mA/V ac Transducer dc mA/V 4-Wire, Select Product
        • SL345 AC and Bipolar Isolator
        • Select Product
      • Select Output
    • Alarm
      • dc mA/V Alarm, Select Output
      • 4-20mA 4-Wire
        • dc mA/V Alarm 4-20mA 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 4-Wire
        • dc mA/V Alarm dc mA/V 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Relay
        • dc mA/V Alarm Relay, Select Product
        • DTA137 Dual Trip Alarm
        • STA138 Single Trip Alarm
        • TRA173 Triple Trip Alarm
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Select Output
    • Isolator
      • dc mA/V Isolator, Select Output
      • 4-20mA 2-Wire
        • dc mA/V Isolator 4-20mA 2-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • dc mA/V Isolator 4-20mA 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SL345 AC and Bipolar Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • dc mA/V Isolator dc mA/V 3-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • dc mA/V Isolator dc mA/V 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SL345 AC and Bipolar Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • dc mA/V Isolator Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • High Drive
        • dc mA/V Isolator High Drive, Select Product
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • Pulse/ Frequency
        • dc mA/V Isolator Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • PWM157 Analog To PWM
        • Select Product
      • Relay
        • dc mA/V Isolator Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Resistance
        • dc mA/V Isolator Resistance, Select Product
        • ATR167 Analog To Resistance
        • ATP168 Analog to Potentiometer
        • Select Product
      • Select Output
    • Transmitter
      • dc mA/V Transmitter, Select Output
      • 4-20mA 2-Wire
        • dc mA/V Transmitter 4-20mA 2-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • dc mA/V Transmitter 4-20mA 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SL345 AC and Bipolar Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • dc mA/V Transmitter dc mA/V 3-Wire, Select Product
        • SI231 Signal Isolator
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • dc mA/V Transmitter dc mA/V 4-Wire, Select Product
        • SL332 Signal Isolator
        • SL335 Signal Splitter
        • SL339 Signal Isolator
        • SL345 AC and Bipolar Isolator
        • SSP235 Signal Splitter
        • HVI237 5KV Isolator
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • dc mA/V Transmitter Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • BSC133 Bipolar Signal Converter
        • BSI134 Bipolar Signal Isolator
        • Select Product
      • High Drive
        • dc mA/V Transmitter High Drive, Select Product
        • BSC133 Bipolar Signal Converter
        • BSI134 Bipolar Signal Isolator
        • PD121 Power Driver
        • PD122 Power Driver
        • Select Product
      • Pulse/ Frequency
        • dc mA/V Transmitter Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • PWM157 Analog To PWM
        • Select Product
      • Relay
        • dc mA/V Transmitter Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Resistance
        • dc mA/V Transmitter Resistance, Select Product
        • ATR167 Analog To Resistance
        • ATP168 Analog to Potentiometer
        • Select Product
      • Select Output
    • Select Function
  • mV
    • mV, Select Function
    • Alarm
      • mV Alarm, Select Output
      • 4-20mA 4-Wire
        • mV Alarm 4-20mA 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 4-Wire
        • mV Alarm dc mA/V 4-Wire, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Relay
        • mV Alarm Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Select Output
    • Isolator
      • mV Isolator, Select Output
      • 4-20mA 2-Wire
        • mV Isolator 4-20mA 2-Wire, Select Product
        • MVT223 Millivolt Transmitter
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • mV Isolator 4-20mA 4-Wire, Select Product
        • SL340 Universal Transmitter
        • SSP235 Signal Splitter
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • mV Isolator dc mA/V 3-Wire, Select Product
        • MVT223 Millivolt Transmitter
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • mV Isolator dc mA/V 4-Wire, Select Product
        • SL340 Universal Transmitter
        • SSP235 Signal Splitter
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • mV Isolator Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • Select Product
      • Pulse/ Frequency
        • mV Isolator Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • Select Product
      • Relay
        • mV Isolator Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Select Output
    • Transmitter
      • mV Transmitter, Select Output
      • 4-20mA 2-Wire
        • mV Transmitter 4-20mA 2-Wire, Select Product
        • MVT223 Millivolt Transmitter
        • SI239 Signal Isolator
        • Select Product
      • 4-20mA 4-Wire
        • mV Transmitter 4-20mA 4-Wire, Select Product
        • SL340 Universal Transmitter
        • SSP235 Signal Splitter
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • dc mA/V 3-Wire
        • mV Transmitter dc mA/V 3-Wire, Select Product
        • MVT223 Millivolt Transmitter
        • SI239 Signal Isolator
        • Select Product
      • dc mA/V 4-Wire
        • mV Transmitter dc mA/V 4-Wire, Select Product
        • SL340 Universal Transmitter
        • SSP235 Signal Splitter
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Bipolar
        • mV Transmitter Bipolar, Select Product
        • BSI234 Bipolar Signal Isolator
        • Select Product
      • Pulse/ Frequency
        • mV Transmitter Pulse/ Frequency, Select Product
        • APC258 Analogue to Pulse Converter
        • Select Product
      • Relay
        • mV Transmitter Relay, Select Product
        • DTI135 Dual Trippoint Isolator
        • STI136 Single Trippoint Isolator
        • Select Product
      • Select Function
    • Select Output
  • Select a Input (above)
  • Select Input

Select products that measure dc input parameters and produce a standard process signal output or an alarm state.

dc Input Products
 

Process Signals

Process signals are a standardised range in an electrical signal that represent a measured value.

For example a signal of 0 to 10Vdc can represent;

  • 100 to 1000kg of butter
  • 0 to 100°C ambient temperature.

The signal is an analogue communication within a standardised range. Common process signals are 4..20mA, 1..5V, 0..20mA, 0..10V, 10..50mA, 0..10mA, 0..1V and 0..5V.

 

4-20mA Input

This will select both auxiliary powered and output loop powered modules.

In most case the APCS signal conditioning module will have the option of supplying the input loop current derived from the auxiliary supply or the loop powered output.

This means the drive voltage could either be coming from the APCS module or the 4-20mA input device.

4-20mA External Source or Input Sourced Concept

4-20mA External Source or Input Sourced Concept

 

Why 4 to 20mA?

The most popular process control signal still used today is 4 to 20mA. It has a number of advantages over zero based and voltage signals.

  • Live Zero Commencement of the scale at 4mA, clearly distinguishes between zero and failure conditions of the signal.
  • Loop Power Signal below 4mA can be utilised to provide power to a loop or signal powered type of transmitter.
  • Noise Immunity The signal information is contained in the 16mA swing (20 - 4). The receiving instrument has typically a low input resistance (10 to 250Ω) which will render the current signal highly immune to electrical interference.
  • Long Cable Length The signal produced by the sensor/transmitter remains constant up to a specified maximum load resistance, so that type and length of cabling used is of little consequence.
  • Safety The low drive voltage required, usually 12 to 24Vdc provides a very high degree of safety.
Auxiliary Powered Transmitter Concept

Auxiliary Powered Transmitter Concept


4-20mA Input Powered

The drive for the 4 to 20mA is derived from the input device.

This current 4mA = 0% of output to 20mA 100% of output also powers the APCS signal conditioning module.

4-20mA Loop Input Powered Concept

4-20mA Loop Input Powered Concept


dc A Input

Select products that accept 1Adc or more. For lower currents use the dc mA/V input selection.

The load current to be measured is wired in series with an internal shunt or passes through a Hall Effect Current Transformer.

Information
 

Shunts Inputs

Some products have an internal wired in series with the load current.

The shunt is a low value accurate resistor. The voltage drop across the shunt is E = I × R.

An accurate millivolt amplifier is then used to create an accurate measurement.

External shunts can also be used with mV measurement products.

50A Shunt

50A Shunt

 

Hall Effect Inputs

The DCT247/8 has a top mounted hall effect CT with link selected ranges from 1A to 100A. For higher currents the DCT247/8 may be used with a range of external hall effect CT's.

The current conductor passes through a magnetically permeable core that concentrates the conductor's magnetic field. The Hall effect device is mounted in the core at a right angle to the concentrated magnetic field. When the energised Hall device is exposed to a magnetic field from the core, it produces a potential difference (voltage) that can be measured and amplified.

Hall Effect Sensor

Hall Effect Sensor


dc mA/V mA and V Input

This selects products that cover the common process signal inputs.

Common process signals include: 4..20mA, 1..5V, 0..20mA, 0..10V, 10..50mA, 0..10mA, 0..1V and 0..5V.

Information

dc mV Input

This selects products that include a high gain precision amplifier that will scale the small input signal to a level stable for processing.

mV transmitters and isolators are used in a wide range of applications where the signal from the sensing probe needs amplification before use.

Information

 

  • dc Input Conditioning
  • Find Product
  • Process Signals
  • 4-20mA Input
  • Why 4 to 20mA?
  • 4-20mA Input Powered
  • dc A Input
  • Shunts Inputs
  • Hall Effect Inputs
  • dc mA/V mA and V Input
  • dc mV Input
  • Footer

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