Channel Config: Bridge Configuration

HGL Software is capable of measuring data using strain gauges depending on which type of HGL Hardware you have (as of April of 2024 this includes units with 1408, 1410-BRG, and 1418 signal conditioning). This article will cover the configuration of channels that are using static strain gauges.

For this example we will be configuring the channel to use a 1/4 bridge strain gauge. First, navigate to the 'Channel Config' page in Hawk GUI.

Next, you will need to set the 'Type' to 'STRAIN' in the drop-down menu on the 'Main' tab of your channel configuration. The 'Units' field should automatically change to 'uStrain'.

When going to Channel Config, you will be on the Main page by default

After setting your channel type to Strain, some additional configuration needs to be done on the 'Sig Cond' tab which can be found near the top of the page.

The Sig Cond tab is located near the top left of your Hawk GUI window

The first thing that needs to be configured is the 'Gauge Type'. For static strain gauges there are 3 options, 'Static Strain 1/4 Bridge', 'Static Strain 1/2 Bridge', and 'Static Strain Full Bridge'. The gauge type setting that you need corresponds with the type of strain gauges you are using.

In this example, the 'Gauge Type' is set to Static Strain 1/4 Bridge

The second thing that needs to be configured is the 'Supply' and 'Source'. The source can be set to either 'Voltage' or 'Current'. The supply is either the voltage supplied or the current supplied dependent on what your source is set to.

In this example, the 'Source' is set to Voltage, and the 'Supply' is set to 1V

The 'Completion resistor' field is only present on channels set to the 1/4 bridge gauge type. The available options are '120 ohms', '350 ohms', and '1000 ohms'. The setting you need will depend on the resistance of your 1/4 bridge strain gauge.

In this example, the 'Completion resistor' is set to 120 ohms

Next, the type of 'Balance Resistor' needs to be selected. The balance resistor is meant to help combat any natural stress in the strain gauge and help balance the bridge circuit while the strain gauge is at rest. The options are 'Open Circuit', 'Fine', and 'Coarse'.

In this example, the 'Balance Resistor' is set to Open Circuit

Finally, the 'Output Mode' needs to be configured. This allows you to chose which point in the bridge circuit you are measuring from. The available options are 'From amplifier', 'From integrator', and 'From ground'.

In this example, the 'Output Mode' is set to From amplifier