Setting a unit up for
a blast.
A ViB stores its trigger as a share of a full-scale range, which is not the number anyone reasons about on site. This is what each setting does, and where the scenarios start from.
What each job starts from
The platform sets a unit up from the job rather than the numbers: where it is, what is being fired, and how far away. These are the rows those answers land on, and the same rows the settings screen applies.
| Scenario | Range | Trigger | In g | In mm/s | Record | Pre-trigger | Rate | GPS |
|---|---|---|---|---|---|---|---|---|
| Open pit · Standard · Near-field | ±40 g | 5% | 2 g | 31 mm/s at 100 Hz | 6 s | 20% | 4000 Hz | Time marks |
| Open pit · Standard · Mid-field | ±10 g | 5% | 0.50 g | 39 mm/s at 20 Hz | 8 s | 15% | 2000 Hz | Position fix |
| Open pit · Standard · Far-field | ±4 g | 1% | 0.04 g | 6.2 mm/s at 10 Hz | 10 s | 10% | 1000 Hz | Position fix |
| Open pit · Large or cast · Near-field | ±40 g | 5% | 2 g | 31 mm/s at 100 Hz | 12 s | 20% | 4000 Hz | Time marks |
| Open pit · Large or cast · Mid-field | ±10 g | 5% | 0.50 g | 39 mm/s at 20 Hz | 16 s | 15% | 2000 Hz | Position fix |
| Open pit · Large or cast · Far-field | ±4 g | 1% | 0.04 g | 6.2 mm/s at 10 Hz | 20 s | 10% | 1000 Hz | Position fix |
| Underground · Development | ±40 g | 2% | 0.80 g | 12 mm/s at 100 Hz | 20 s | 10% | 4000 Hz | Off |
| Underground · Production | ±40 g | 2% | 0.80 g | 12 mm/s at 100 Hz | 30 s | 13% | 4000 Hz | Off |
| Construction · Blasting · Near-field | ±40 g | 5% | 2 g | 31 mm/s at 100 Hz | 6 s | 20% | 4000 Hz | Time marks |
| Construction · Blasting · Mid-field | ±10 g | 5% | 0.50 g | 39 mm/s at 20 Hz | 8 s | 15% | 2000 Hz | Position fix |
| Construction · Blasting · Far-field | ±4 g | 1% | 0.04 g | 6.2 mm/s at 10 Hz | 10 s | 10% | 1000 Hz | Position fix |
| Construction · Ongoing vibration | — | — | — | — | — | — | 1000 Hz | Left as set |
The velocity column is a pure-tone figure at the frequency each scenario is usually read at — a planning bound, not a measurement. A unit resolves these against its own sensor and firmware, and the settings screen says whenever it had to.
What each one does
Six settings decide what a unit captures and what makes it start. Every one of them is a trade, and the number that matters is named in each.
Recording mode
How the unit decides what to keep. Active waits, then records a full waveform each time movement crosses the trigger level — the mode for a blast. Passive records all the time and reports peaks every 5 minutes, which is what ongoing vibration monitoring near neighbours needs; nothing has to trigger it. Peak vector sum keeps the largest combined movement in each window without the waveform, on the units that offer it.
Sample rate
How often the unit takes a reading. A higher rate resolves sharper peaks, which matters close to a shot where the motion is fast, and it shortens the longest recording the unit can hold — the same memory divided into more readings a second. Prefer 2000 Hz or above when the peak itself is the answer you need.
Record time
How long each recording runs once it starts. Long enough to hold the whole event: a single shot is over in seconds, a cast shot or a production ring runs on. Set it too short and the tail is cut off; too long and the unit fills its memory with quiet. The unit caps it, and the cap depends on the sample rate.
Range
The largest force the unit can measure. Above it the peak clips and the recording is worth less than nothing, because it looks like a smaller event. Close to a blast, take the headroom. Far away, a lower range resolves finer motion — and because the trigger is a share of the range, changing the range moves every trigger level with it.
Trigger level
The level, as a share of the range, that starts a recording. Lower catches smaller events and more of everything else: handling the unit, a truck going past, someone leaning on the housing. This is the setting worth reading in mm/s, because that is the unit a compliance limit is written in.
Pre-trigger
How much of each recording is kept from before the trigger fired, as a share of the record time. The run-up to a shot is part of the event, and without it the first arrival is the first thing missing. A fifth of the record is a sound default.
What the GPS setting is for
A unit stores one GPS setting and it answers two different questions. Splitting them is the difference between guessing at "continuous" and knowing what you get.
Position
Every recording is stamped with where the unit was. It can come from the unit’s own GPS, from the phone or computer you are connected with, or from coordinates typed in by hand — and a hand-set position wins over any fix the receiver has. That is the rule to remember: if someone has set the position by hand, that is what gets stamped until it is cleared, even with GPS on.
GPS time marks
A unit’s own clock is good to about a second. That is fine for one unit and useless for several, because lining up recordings of the same blast from three units needs them to agree far more closely than that. With time marks on, the receiver stays awake and stamps each trigger against GPS time, which is the only absolute time a ViB produces — and the platform then draws all three on one timeline.
What it costs
Keeping the receiver on costs battery, which matters over a multi-day armed window and not at all over an afternoon. A position fix alone does not: the unit wakes the receiver when a recording starts and puts it back to sleep. Underground, where there is no sky, both are off and the unit is timed from whatever device armed it.
Common questions
What happens if I get the range wrong?
Too low and the peak clips: the recording shows a flat top and understates the event, which is the one failure you cannot correct afterwards. Too high and you lose resolution on small motion, which usually only costs you some detail. Close to a blast, take the headroom.
Why is my trigger in percent and not mm/s?
The unit triggers on acceleration and stores the level as a share of its full-scale range, so the same 5% is a different force on a ±4 g unit and a ±40 g one. The settings screen converts it for you: switch the trigger to mm/s and pick the frequency your site is assessed at.
Do I need GPS time marks?
Only if more than one unit is recording the same blast and you want the recordings on one timeline. For a single unit the clock it is given when you arm it is enough, and leaving time marks off saves battery over a long armed window.
The unit did not keep the settings I sent. Why?
Firmware clamps anything it cannot hold — a record time longer than its memory allows at that sample rate, a range its sensor does not offer, a GPS mode its dialect does not have. The settings screen always shows what the unit stored rather than what it was sent, and it says which values changed.
Can I set the position without a sky view?
Yes. Enter the coordinates by hand, or set them from the phone you are connected with. Either writes the position straight to the unit and it is used for every recording until you clear it.
Read the trigger in the units your limit is written in
Acceleration and particle velocity are the same event in two languages. The companion guide has a working model of the conversion.
Both guides use the same arithmetic as the ShockAI platform.