High Precision Portable Signal Generators and Calibrators: Everything You Need to Know

High precision portable signal generators are portable electronic devices that generate highly precise signals for testing, system calibration, sensor simulation, troubleshooting, and monitoring. Unlike the benchtop signal generators that are used in laboratories, these hand-held portable devices are designed to be used in the field. The best high precision portable signal generators are also rugged and NIST traceable, meaning that their manufacturer calibrates them to standards from the National Institute of Standards and Technology (NIST).

In terms of cost, high precision portable signal generators are more expensive than less precise, lower-end devices that can be held in the hand; however, these inexpensive devices cannot generate signals with a high degree of accuracy. Whether you need them for general-purpose uses or industry-specific applications, high-precision signal generators produce realistic signals of the highest integrity and with a degree of accuracy that’s very close to the instrument’s setting. Applications include sound and vibration detection and calibration for rotating equipment, gas turbine engines, and data acquisition systems.

What makes high precision portable signal generators different?

Typically, very accurate signal generators are found only in laboratories. With a high precision portable signal generator, however, a field technician has access to an electronic testing device that delivers a precisely calibrated signal ranging from audio frequencies to the microwave range. Whether the signal that’s produced is adjusted according to output, voltage, frequency, waveform, impedance, and modulation, there is always a high degree of accuracy.

High precision portable signal generators can be used in outdoor environments such as aircraft flight lines, but they also have indoor applications at power plants and industrial facilities. These electronic testing devices feature a compact, lightweight design and a spill-proof keyboard. Because they are rugged, they can be moved or shipped between locations without damage. By contrast, benchtop signal generators that are designed for laboratory use may have a high degree of precision and NIST traceability but lack portability and ruggedization.

How do you select high precision portable signal generators?

Products can vary considerably, so it’s important to look for a device that is portable, precise, rugged, NIST traceable, and that meets applications-specific requirements in the following areas.

  • Accuracy: High precision devices provide voltage and frequency signals with up to 0.05% accuracy in a range from DC to 100 kHz.
  • Frequency Synthesizers: Some signal generators are only for single-frequency applications; however, higher-end models feature two independent digital synthesizers. These dual-frequency synthesizers provide accurate and independent control of signals.
  • Signal Outputs: Basic signal generators have a single-mode signal-output system; however, more advanced devices have dual outputs that can be synchronized in simulations that address velocity and charge.
  • Multiple Output Wave Shapes: Signal generators can produce different waveforms. During product selection then, it’s important to determine whether a device generates square, sine, sawtooth, and triangle waveforms, or just some of these wave shapes.
  • JOG Function: High precision portable signal generators with a JOG function allow users to slowly change the output signal parameters to help find critical signal values or detect “sweet spots.” This feature promotes ease-of-use, but it’s not available with every available product.
  • Rechargeable Batteries: Devices with integral nickel-metal hydride (NiMH) batteries can operate for several hours on a single charge. This promotes productivity since users don’t have to stop work to recharge the instrument.
  • Programming Port: A high precision signal generator with a built-in universal serial bus (USB) port permits re-calibration and pre-programming. Features like this promote ease-of-use and enable technicians to spend more time using the device instead of getting ready to use it.
  • Digital Inputs and Displays: High precision signal generators that are digital instead of analog don’t use knobs or dials that can be difficult to adjust in small increments. Digital devices can also have backlit displays that are easier-to-read.

What else do you need to know about high precision portable signal generators?

High precision signal generators are used to calibrate monitoring systems, charge amplifiers, and avionics equipment. Applications include:

  • charge amps on rotating equipment to test vibration
  • audio signal simulation
  • wire and cable troubleshooting
  • low-voltage bridge sensor signal simulation
  • machinery speed signal simulation
  • vibration signal simulation (accelerometers and velocity probes)

For an example of high precision portable signal generator that’s used in these and other applications, see MTI Instruments’ 1510A.