Amplifiers

Amplifiers

Force Measurement

Amplifiers

bf1systems are now able to offer three different strain gauge amplifiers (in-line, intelligent and dual gain), meaning there is one to suit every application.

The in-line high precision amplifier is a dedicated amplifier, designed to operate in conjunction with full-bridge strain gauge installations.

It is housed in a  compact aluminium casing and is fitted with Souriau size 2 connectors.
The amplifier gain and offset voltage can be either selected from the standard range or alternatively a custom amplifier for a particular installation can be supplied. The gain accuracy of the custom amplifiers can be trimmed to 0.1% (please contact bf1systems for more information on custom options).
We can also supply the amplifiers without housings if it is preferred to mount within your own housing.
The bf1systems intelligent amplifier uses a microprocessor to measure the temperature of the strain gauges and applies a correction at each temperature step for the offset and span errors in the calibration.
This removes the inherent error which most strain gauge installations suffer from when exposed to temperature variations.
This results in outstanding accuracy results in data more accurate than from even the best compensated gauges.
The dual gain intelligent amplifier provides the same functionality as the standard intelligent amplifier, but features two outputs, that can have different gains and offsets applied to them.
This allows a team to analyse both aero and dynamic loading on a single set of components.

Intelligent Amplifier

Intelligent Amplifier

The bf1systems intelligent amplifier corrects the errors normally associated with standard strain gauge installations, producing a part which is unaffected by temperature changes, and which can have the same calibration across multiple parts, removing the need to update loggers when parts are replaced on the car.

Strain gauged components have inherent accuracy problems; temperature effects on a strain gauge are not linear, gauges are affected by temperature gradients across the gauged part and each strain gauge has a different calibration.

When a strain gauged component is temperature compensated by standard methods the offset compensation is only performed at two temperatures and the effects minimised at these points. What happens at other temperatures can lead to unexpected errors in the load cell.

As the temperature effects are non-linear the errors can be quite significant.

The bf1systems intelligent amplifier measures the temperature of the strain gauges, applies a correction at each temperature step for offset and span errors in the calibration. Thereby producing an output that is far more accurate than even the best compensated gauges.

As the system is microprocessor controlled, we can calibrate the system gain to provide a standard output for every part in a set. There is no need to enter a specific part calibration and therefore there is no chance of mistakes when entering the calibration.

Each part is individually calibrated in a computer-controlled oven over a full load and temperature range and each part retains its own unique calibration table.

The miniaturised design of the system allows the sensor electronics to be mounted directly on the rod end, track rod, steering column or any other load bearing part. Due to the sensor electronics being very close to the strain gauging, signal noise is reduced to a minimum. The output is a low impedance 0-5V signal that does not require screening or separate amplification.

Typically, this system would produce a rod-end load cell with a 0.5-4.5V output measuring 0-4000kgf, with every part having the same calibration of 1000kgf/V. This calibration factor is user definable as is the zero offset.

To benefit fully from the system, the gauged part has to be a suitable shape for strain gauging. Many parts that are strain gauged are not suitable for the job and introduce errors that cannot be removed by any means.

Due to the unique nature of each customer’s installation, our in-house design team may recommend modifications to existing parts. We can also design or consult on the shape of strain gauge parts for maximum accuracy.

We offer a full design, consultation and manufacturing service for the bespoke parts of the system and aim to deliver a customised system as a complete package.

Electrical

  • 7 – 18 Volt supply range
  • Non-ratiometric output, supply voltage changes do not affect the output.
  • Supply current <30mA
  • High level 0 – 5V output, no requirement for additional strain gauge amplifiers
  • Identical output for all parts, no calibration data entry for each part
  • Thermal zero shift over compensated range 0.1% FSO
  • Thermal sensitivity shift over compensated range 0.2% FSO
  • Internal 150Hz 2–pole low-pass Butterworth filter

Environmental

  • Compensated temperature range 10°C to 125°C
  • Operating temperature range 0°C to 125°C
  • Sealed to IP65

Dual Gain Amplifier

Dual Gain Amplifier

The bf1systems dual gain intelligent amplifier is based on the current motorsport proven intelligent amplifier, but now features two separate
0 – 5V outputs with individually scalable gains and offsets. This allows the logging of two channels of push rod load data, allowing a part to be
optimised for both dynamic loading conditions and aero balance analysis.

With track testing time now at a premium, the dual gain intelligent amplifier allows engineers to look closely at aero balance during race

weekends, and also allows race spec push rods to be used during dedicated straight line testing, minimising a team’s part count.

The bf1systems dual gain intelligent amplifier has been specifically designed to prevent the issues normally associated with standard amplified strain gauge installations, which include:

  • When a strain gauged component is temperature compensated by standard methods the offset compensation is only performed at two temperatures, with the effects being minimised at these points. No other temperatures are compensated, which can lead to non-linear behaviour, and can lead to unexpected errors in the load cell. The bf1systems dual gain intelligent amplifier measures the temperature of the strain gauges, applies a correction at each temperature step for offset and span errors in the calibration, and therefore produces a linear output that is far more accurate than even the best compensated gauges.
  • Standard strain gauged parts often have individual calibrations, which require corresponding calibrations to be entered into the logger when the part is fitted to the car. The dual gain intelligent amplifier is microprocessor controlled, and each part in a set can be calibrated to provide a standard output, therefore removing the need to enter a specific part calibration and removing any chance of mistakes when entering the calibration. Each part is individually calibrated in a computer-controlled oven over a full load and temperature range, and retains its own unique calibration table.
  • Other strain gauge installations have the amplifier separate to the stain gauging, which can lead to signal noise. The dual gain intelligent amplifier has a miniaturised design, which allows the sensor electronics to be mounted directly on the push or pull rod. Due to the sensor electronics being very close to the strain gauging, signal noise is reduced to a minimum. The outputs are a 0-5V signal that does not require screening or separate amplification.
  • Many strain gauged parts have not been designed with gauging in mind, therefore when the part is strain gauged, inherent errors are present, which cannot be removed by any means. bf1systems’ in-house design team work with customers from the start of a project to ensure parts are optimised for strain gauging, to give the best possible results. bf1systems also offer a full design, consultation and manufacturing service for the bespoke parts of the system, and can deliver a customised system as a complete package.

Electrical

  • 7 – 18 Volt supply range
  • Non-ratiometric output, supply voltage changes do not affect the output.
  • Supply current <10Ma
  • Two high level 0 – 5V outputs with individually scalable ranges, with no requirement for additional strain gauge amplifiers
  • Identical output for all parts, no calibration data entry for each part
  • Thermal zero shift over compensated range 0.1% FSO
  • Thermal sensitivity shift over compensated range 0.2% FSO
  • Internal 150Hz 2–pole low-pass Butterworth filter
  • Output connections: 1 = UNIT SUPPLY (+VE) 2 = UNIT GROUND (-VE) 3 = OUTPUT 1 4 = OUTPUT 2

Environmental

  • Compensated temperature range 10°C to 125°C
  • Operating temperature range 0°C to 125°C

In-Line Amplifier

In-Line Amplifier

bf1systems in-line high precision amplifiers are dedicated amplifiers, designed to operate in conjunction with full-bridge strain gauge installations.

The GEN2 amplifier incorporates the same electronics as our GEN 1 amplifier but is housed in a more compact aluminium casing and is fitted with Souriau size 2 connectors.

The amplifier gain and offset voltage can be either selected from the standard range or alternatively a custom amplifier for a particular installation can be supplied. The gain accuracy of the custom amplifiers can be trimmed to 0.1% (please contact bf1systems for more information on custom options).

We can also supply the amplifiers without housings if it is preferred to mount within you own housing.

Electrical

  • 7 – 18 Volt supply range
  • Non-ratiometric output, supply voltage changes do not affect the output.
  • Full scale output 0.02 to 4.98V
  • Non-linearity +/-0.01% FSO
  • Hysteresis +/-0.01% FSO
  • Thermal zero shift over compensated range 0.002FSO/°C
  • Gain and offsets available to requirements
  • Excitation output 5V +/-0.1% FSO
  • Input connector 8STA00205SA – 1 = EX+, 2 = SIG-, 3 = SIG+, 4 = SCR, 5 = EX-
  • Output connector 8STA00205SN – 1 = 12V, 2 = SIG, 3 = GND

Environmental

  • Compensated temperature range 10°C to 125°C
  • Operating temperature range 0°C to 125°C

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Owen Road
Diss
Norfolk
IP22 4ER
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CONTACT

Technical Centre
Owen Road
Diss
Norfolk
IP22 4ER
United Kingdom

View Map >