What's in the box.
A single sensor, a USB-C cable, and the bits you need to attach it to a machine. The Balancer kit adds a clip-on IR tachometer.
The sensor, up close
- AStatus LEDTop-face. Red on boot → amber while the radio comes up → solid green when the captive portal is live.
- B3.5 mm tach inputBalancer kit only. Accepts the bundled IR tach sensor. TRS; signal on tip, power on ring, GND on sleeve.
- CUSB-C power5 V, 200 mA typical. Any phone charger, laptop port, or battery bank works. No data link — power only.
- DMagnetic baseHolds firmly to any ferrous housing. For aluminum or plastic, use the bundled VHB strip.
Mount and power.
Fifteen minutes, five steps. Get the sensor onto the machine and the LED solid green.
TACH port. Tip: the vibration analyzer can also mount to the mag base's V-block bottom for easy clamping on round housings.Connect your phone.
The sensor runs its own Wi-Fi access point and a captive portal. No app. No account. No internet.
Open Wi-Fi settings
On iOS: Settings → Wi-Fi. On Android: Network & internet → Internet. You'll see a network named GV-#### — the four characters are your device's unique ID, printed on the label. Connect to that network.
Join the sensor's network
Tap GV-#### (your device number). No password. The captive portal should open automatically — if it doesn't, navigate directly to http://gv-####.local in your browser.
The dashboard opens
The captive portal loads the measurement dashboard in your phone's built-in browser — the same UI you'll see embedded throughout the rest of this guide. Nothing to install. Close the page to disconnect.
The Live view.
The screen you land on. Purpose: confirm the sensor is attached correctly and read the current health of the machine in under three seconds.
What to look for
1× TACH badge tells you the source.How the verdict is computed
Spectrum — reading the frequency domain.
The FFT tells a story. Once you know where to look, you can read it in seconds. The Spectrum view is where you diagnose what is wrong, not just that something is wrong.
Run a balance job.
Single-plane influence-coefficient balancing. Four runs. GrayVolt tells you exactly where the trim weight goes and how much.
Why the polar is the hero
Most portable balancers print the answer as two numbers in a spreadsheet cell: "3.2 g at 214°." It works, but you're flying blind.
The polar shows the tech why. As each run completes, a new vector appears in the plot. You can watch how the machine responds to the trial weight, and see at a glance whether your correction is shrinking the imbalance or just moving it around — no mental math required.
Log & history.
A flash-backed ring buffer of every significant event since the device was powered on. Think of it as the black box — useful when something goes wrong and you need to correlate with the machine controller's logs.
gv-log-YYYYMMDD.json. CSV variant is firmware-side because it's size-bounded.Settings & calibration.
Everything that isn't a live measurement. Wi-Fi mode, tach calibration, and the upgrade-code field.
Troubleshooting.
The short list. If something here doesn't solve it, email the team — we read every message.
TachTach trigger dot isn't pulsing
The sensor isn't seeing pulses from the IR tach.
· Check the 3.5 mm cable is seated fully in the TACH port.
· Aim the IR head at the sharpie mark, not bare shaft. Standoff: 5–25 mm.
· In Settings → Tach calibration, open the live ADC trace and spin the shaft by hand. You should see a clean square pulse. If it's a noisy sine, the IR head is too close or the mark is too faint.
· Re-darken the sharpie mark if it has worn or faded.
Wi-FiPhone connects, but no dashboard loads
The captive portal didn't intercept automatically.
· Open Safari or Chrome and navigate directly to http://gv-####.local or http://192.168.4.1.
· iOS caches DNS aggressively. Toggle airplane mode off/on.
· If the page loads but the connection pill says Reconnecting, you're probably on both the sensor AP and cellular — iOS sometimes routes the WebSocket through cellular. Turn cellular data off on that tab.
NoiseNoise floor is unusually high
The broadband floor between harmonics should be low and flat.
· Check the sensor is firmly seated. Loose mounts read as broadband noise.
· Remove VHB residue from the housing and re-mount. A clean surface is critical.
· If mounting on aluminum with the magnet, swap to VHB — a gap of even 0.5 mm adds a resonance around 800 Hz.
· Check the machine coolant isn't dripping on the sensor. The IP rating is splash-proof, not immersion-proof.
BalanceBalance job never converges
The correction weight doesn't reduce 1× after the solution run.
· Trial weight was too small — the trial response should be clearly distinguishable from the baseline. Try a larger trial weight.
· Run-to-run repeatability is poor. Something else is changing between runs: coolant on/off, ambient temperature, fixturing. Lock those down, then re-baseline.
· The imbalance is in a different plane. Single-plane balancing assumes the weight is concentrated axially; if the imbalance is distributed along the shaft, you need two-plane balancing (future firmware module).