Alarms, Amplifiers, and Transmitters for Strain Gauge, Bridge, Pressure Transducer or Sensor, Load Cell Applications

lifetime warranty
  • Lifetime Warranty on API Modules
  • LoopTracker® I/O LEDs
  • Hot-Swappable Plug-In Design
  • Zero and Span Xmtr Output Calibration
  • Push to Test Output
  • Full I/O/Power Isolation
Click on PDF links below
for product information

Literature and Links


API product brochure
Options & accessories
Regulatory Compliance page

Reference Info


Troubleshooting strain gauge sensors
LoopTracker and Output Test
Sink vs source
Alarm terminology
Deadband
Relay protection & EMI suppression

UL Approvals

API modules USA
API modules Canada

APD modules USA
APD modules Canada

Amplifiers for

  • Load Cells
  • Weighing Systems
  • Pressure Transducers and Sensors
  • Strain Gauges
  • Wheatstone Bridges
  • Force Transducers and Sensors

Application Notes


Chemical plant
Platform scale
Truck scale
Dispensing system automation
6-Wire strain gauges
Pressure sensor vs. pressure transmitter
Pressure transducer calibration
Weighing shipping containers
Pressure system calibration
Pressure transducer calibration
Plastic extruder pressure
Extrudung guitar strings
Custom product for high speed pill presses

How to Order

  1. Select a model
  2. See data sheet for ordering info and options
  3. Note that options affect pricing
  4. Request a quote via chat or call us
  5. 2-5 day typical lead time + shipping time
  6. 5-10 day lead time for quantities of 5 or more + shipping time
  7. To place your order
Model Input/Output Features Product

Isolated DC Amplifier for 1 to 4 Sensors:

  • Load Cells
  • Pressure Transducers and Sensors
  • Strain Gauges
  • Bridges
  • Force Transducers and Sensors

Field Selectable Minuteman Setup


API 4059 G  from $389

Open Datasheet
Download Datasheet
Email Datasheet Link
Field configurable
0-5 mVDC to 0-400 mVDC, 120 mA
Accepts one to four sensors for input

Field settable excitation voltage
0-10 VDC in 1 VDC steps

18 field configurable outputs
0-1 V to ±10 V
0-2 mA to 0-20 mA, 4-20 mA
Zero Offset (Tare) ±100% of span in 15% increments
  • Minuteman one-minute setup
  • I/O LoopTracker LEDs
  • Full I/O/power isolation
  • Internal Bridge Excitation Source
  • Drive up to 4 bridges
  • Output test button
  • Uses API-011 11-pin socket
  • 115 VAC powered
  • A230 option for 230 VAC
  • D option: 9-30 VDC power (+$60)

Api 4059G
API 4059 G
Socket sold separately

Isolated DC Amplifier for 1 to 4 Sensors:

  • Load Cells
  • Pressure Transducers and Sensors
  • Strain Gauges
  • Bridges
  • Force Transducers and Sensors

Field Selectable Minuteman Setup


APD 4059  from $409

Open Datasheet
Download Datasheet
Email Datasheet Link
Field configurable
0-5 mVDC to 0-400 mVDC

Field settable excitation voltage
0-10 VDC in 1 VDC steps, 120 mA
Accepts one to four sensors for input

18 field configurable outputs
0-1 V to ±10 V
0-2 mA to 0-20 mA, 4-20 mA
  • Minuteman one-minute setup
  • I/O LoopTracker LEDs
  • Full I/O/power isolation
  • Internal bridge excitation source
  • Drive up to 4 bridges
  • Output test button
  • DIN rail mount
  • 22.5 mm Wide
  • Universal power 85-265 VAC, 60-300 VDC
  • Option D for 9-30 VDC, 10-32 VAC power

APD 4059UL approved
APD 4059

Isolated DC Amplifier for 1 to 4 Sensors with
Calibration Resistor Option for:

  • Load Cells
  • Pressure Transducers and Sensors
  • Strain Gauges
  • Bridges
  • Force Transducers and Sensors

Field Selectable Minuteman Setup


APD 4059CR  from $449

Open Datasheet
Download Datasheet
Email Datasheet Link
apd4059cr Field configurable input
0-5 mVDC to 0-400 mVDC

Field settable excitation voltage
0-10 VDC in 1 VDC steps, 120 mA
Use internal or external calibration resistor
Specify calibration resistor value if required
Accepts one to four sensors for input

18 field configurable outputs
0-1 V to ±10 V
0-2 mA to 0-20 mA, 4-20 mA
Zero Offset (Tare) ±100% of span in 15% increments
  • Lifetime warranty
  • Minuteman one-minute setup
  • I/O LoopTracker LEDs
  • Full I/O/power isolation
  • Internal bridge excitation source
  • Drive up to 4 bridges
  • Calibrations switch
  • DIN rail mount
  • 22.5 mm Wide
  • Universal power 85-265 VAC, 60-300 VDC
  • Option D for 9-30 VDC, 10-32 VAC power


APD 4059UL approved
APD 4059CR
Discontinued Strain Gauge
API 1500 G
1520 G
Bridge Input Single Alarm Trip. See APD 1500 series
API 4051 G Bridge to DC Signal Conditioners, Non-isolated. See API 4051 GI
API 4059 DIN Isolated Bridge to DC Signal Conditioners. See APD 4059
API SUM-000
API SUM-025
Bridge Summing Board. See SG-EQ4SG-EQ4 (scroll down)
API SUM Board Bridge Summing Board Detailed Instruction Manual
APD 1530 Strain Gauge Input Band Alarm Trip