Calibration

Calibration in openJII is done at a bench: the device is connected to your computer, the browser runs a calibration procedure against it and any reference instruments, a script fits coefficients from the readings, and you decide whether to apply them. Completed captures are kept on the device's record, so you can see which coefficients are in force and where they came from. Stopping a capture before it finishes leaves no run on record.

What you need

• A device registered in Devices that you can contribute to. Recording a bench run requires contribute access; approving, rejecting or writing it needs Can edit on the device, or Owner or Admin of the organization that owns it. Only people who can manage a device see its Calibration tab.
• A Chromium-based browser on a desktop. The browser is the bridge to the hardware over Web Serial; without Web Serial, Run at the bench stays disabled.
• The reference instruments the procedure names, each on a serial port of its own.

Calibration procedures

Calibrations in the sidebar lists the procedures you can see, with their device family, visibility and when they were last updated. A procedure says which device family it is for, which instruments the bench needs, the steps it walks, the coefficients it produces and the script that fits them. Its page shows these as The rig it needs, What it does at the bench, What it produces and How it fits, with the device family and minimum firmware in the details beside them. A run on firmware older than that minimum is refused.

New calibration creates a procedure straight away, named "Untitled calibration" and set up for a MiniPAR, and opens it so you can edit it. Once a run has recorded a procedure, it can no longer be edited or deleted; use Duplicate to start a new one from it. Duplicate is also how you change a procedure someone else owns: the copy is yours. A procedure no run has recorded can be removed with Delete.

Calibrate a device

Start from the device's Calibration tab with Calibrate, or from a procedure's page with Run at the bench. The wizard has six steps.

1. Procedure. Pick the procedure for this device.
2. Connect. Select Connect device and choose the device's port, then connect each instrument the procedure needs. The run cannot start until the device answers as the family the procedure is for and every required instrument is connected. Started from a device, the wizard also checks the serial number the unit reports against that device's record, and a different serial stops the run; a unit that reports no serial cannot be checked, so make sure the right one is on the port. Started from a procedure's page, the wizard matches the unit to one of your registered devices by its serial, or asks Which device is this? when the firmware does not report one.
3. Capture. Start the run walks the procedure and records each reading. Answer what it asks along the way. When answering a prompt sets off readings, the prompt names them: the run goes on to take them without asking again, so set everything up before you select Continue or Record. Stop ends the run without recording anything.
4. Review. The result lists each block and the coefficients of any block that computed. If the script supplies a quality verdict, the card shows Quality gates passed or Quality gates failed. R² and NRMSE appear when the script supplies those numbers with the verdict. A chart appears when the result includes usable fitted-point data or vector coefficients. Approve applies the computed coefficients to the device's record, replacing any earlier ones for the same block. Reject applies nothing and keeps the run on record. Only a run that produced coefficients can be approved. Approving does not touch the hardware.
5. Write. Write to device writes each approved block and confirms it by reading it back. A block that is not confirmed may have reached the device in part, so run the calibration again before trusting the device. Finish without writing leaves the coefficients approved on record only.
6. Done. A summary of what was measured, approved and confirmed on the device. Started from a procedure's page, it also links to the device's Calibration tab, where the run is kept.

Only MiniPAR and Ambit coefficients can be written to the device. For every other family, including MultispeQ, the write step says the calibration is approved on record only.

What is in force

A device's Calibration tab shows the In force card and the Bench sessions list. In force shows the coefficients the device's record holds, since when, and whether they were Written to device, are Not yet written to device, or were Written but not confirmed. The device's overview has a Calibration card with the date it was last calibrated and a link to this tab.

Each bench session keeps its status (Running, Computed, Compute failed, Error, Approved or Rejected), what the bench measured, the review and any write. Opening a session that is still waiting for a decision gives you Approve and Reject. A session that was approved but never written offers Write to device, so you can write it later from the bench.

For the measurement side of each device, see MultispeQ and Continuous sensors.