| Item | Requirement |
|---|---|
| Device | iPhone. The app is designed for the iPhone screen. |
| System | iOS 17.0 or later. |
| Camera | For recording: a 240 fps format supported by the selected camera, typically the main rear camera. The app checks the available formats; verify compatibility on the individual device. For imported videos, the actual frame rate, timestamps and original file quality matter. |
| LiDAR | Optional, on supported Pro models: measures the phone-to-control-panel distance for the acoustic trigger. Alternatively, measure and enter the distance manually. |
| Network | Analysis, calculations and content are local; paid features require a valid entitlement. Apple purchases, purchase restoration and timestamp requests need a network connection. The app shows pending or failed timestamp requests. |
| Permissions | Camera, microphone, photo library and motion sensors, each only asked when needed. The reason for each is in the privacy information. |
| Field equipment | Tripod or magnetic support; a mirror if the light curtain LED is outside the frame; the specified test piece for the detection-plane crossing trigger. |
StopTime · Support
Support
Requirements, recordings, calculations, reports, timestamps and purchases. The guide to StopTime 1.0.0 for iPhone, available on the App Store. Updated to 1 October 2026.
Version 1.1.0 adds English: Italian is selected automatically when the iPhone's primary language is Italian; English is used for every other language. You can change this in setup or About > Settings > Language. This update is being prepared for App Store review. The screenshots shown here are from the released Italian version.
Support contacts
Write "StopTime" in the subject. It's the fastest channel: you can attach screenshots and, if you want, the recording.
For a quick answer, indicate
- iPhone model and iOS version
- App version, in the Information screen
- Workflow step and selected trigger
- Screenshot of the message or the result
The recordings may show people, installations and confidential information: send them only if necessary and if you are authorised to do so. The data you send to us are processed in accordance with the privacy notice of the app.
Requirements
What is needed.
Quick guide
The measuring path, in ten steps.
Each screen shows Step n of 10. Complete the workflow and save the session to retrieve it from Archive. Do not rely on an incomplete workflow to retain the test record.
Before using Measure or Calculate, read terms v2.1. The app requests one general acceptance, not selected in advance. The declaration required for each report is separate and does not constitute a signature or professional approval. Learn and Archive viewing remain available without a subscription.
- Measure: tap New measurement, or Quick check to find the maximum stopping time allowed by an existing installed distance.
- Machine: enter its designation, manufacturer, model and moving part; you can photograph the nameplate. The machine is available in Archive for later checks.
- Protective device: type and direction of approach, edition of EN ISO 13855, detection capability d and catalogue response time t₁.
- Trigger: A · Acoustic, B · LED, B′ · Reflected LED or C · Detection-plane crossing. Check the stated conditions. D · Two phones is unavailable in this version.
- Framing: select the moving-part and LED regions; the app checks the format and frame rate.
- Recording: record 3 to 5 seconds per repetition, with the machine moving when the protective device is triggered.
- Analysis: check and confirm the triggering and stopping events using the frames and plots.
- Repetition result: measured t₂, uncertainty U and declared value. Plan repetitions under relevant conditions and read the warnings about test count and the criterion for the selected standard edition.
- Calculation of S: in supported cases, S distance on the value adopted for the session, installed distance, margin and guard band. If the case requires data tables not included, refer to the indicated reference: the app does not produce S nor a numerical comparison. You can retain the time measurement and a draft with an outcome of “Not evaluated”. A numerical comparison is not a judgment of machine conformity.
- Report: title, declared operator, use acknowledgement, draft PDF and saving to Archive. Printing and sharing require Single Report access or Unlimited.
Try without a machine
The demonstration video
The app contains a synthetic video at 240 fps to familiarize yourself with the path on the desk. The data and demonstrative calculations do not validate a real measurement.
- Measure › New measurement; enter the machine and device details.
- Choose trigger B · LED in frame.
- In Framing touch Try with the demonstration video, then Analyse.
Expected result: trigger at frame 100, stop at frame 145, measured t₂ of 187.5 ms. Measure requires Base, Unlimited or an active Base trial. Any timestamp evidence labelled as test data in the demonstration does not attest to a real test.
Recording tips
Plan the measurement before pressing Record.
The recording must show two identifiable events on the same timeline: device triggering and the end of motion. At 240 fps, one frame is 4.17 ms, equivalent to 8.3 mm at K = 2000 mm/s. Take care to preserve temporal resolution. The complete guide is in the app's Field Recording Guide article.
Keep the phone still
Tripod or magnetic stand, never by hand. Optical axis perpendicular to the direction of motion: a motion along the optical axis cannot be seen and cannot be measured.
Two events, one recording
Moving part and LED, or its reflection in the mirror, in the same frame and in separate areas. Better if at the same height: the sensor reads the lines from top to bottom.
Sharp edges
The moving-part region must contain clearly visible features: edges, holes or markings. A smooth, uniform surface cannot be tracked reliably.
Bright, continuous lighting
At 240 fps the exposure is short and requires a lot of light. The lamps powered by the network at 50 Hz pulse at 100 Hz: if the flickering disturbs the LED reading, prefer a continuous light source.
Clean audio
For an acoustic trigger: keep the microphone unobstructed, disconnect audio accessories and ensure the click is clearly audible above background noise. Measure the phone-to-control-panel distance: sound arrives approximately 2.9 ms later per metre at 20 °C.
Useful repetitions
Record 3 to 5 seconds per repetition, with the moving part stationary for at least 6 frames before the end. Repeat under relevant speed, load, position and temperature conditions. The session criterion depends on the selected edition: for 2024, the app warns if there are fewer than ten repetitions.
Videos recorded with the Camera app
Transfer the video without losing the 240 fps.
When you record from StopTime, the problem does not occur: the capture is internal. If you, on the other hand, analyse a slow motion recorded with the Camera app or received from a colleague, you need the original file . Many standard methods deliver a file encoded at 30 fps: it may lose the temporal resolution and audio necessary for the test.
They preserve the original
- AirDrop with Options › "All photo data".
- USB cable: first select Settings › Photos (from iOS 18: Settings › Apps › Photos) › Transfer to Mac or PC › Keep Originals on the iPhone.
- Photos on Mac: File › Export › Export Unmodified Original.
To avoid
- Share from the standard menu, with Mail or Messages: the video can be converted into a more compatible format.
- In Photos on Mac, Export 1 Video re-encodes the video.
- Trimming or editing the slow-motion video in Photos before exporting it.
As a final check, read the actual frequency and the alerts shown in the analysis. The SHA-256 fingerprint identifies the analysed file: comparing it with the fingerprint of an original stored allows you to verify its identity, not to reconstruct lost data through a conversion.
Calculate and Learn
Formulas, steps and study.
Calculate includes 10 tools for distances, allowable times, wear allowance, parallel approach, video uncertainty, acoustic delay, rolling shutter, statistics, kinematics and converting milliseconds to millimetres. Find a tool, enter the data and check the edition, units, steps and warnings. Use favourites to find it again. Calculator PDFs are included in Base and Unlimited. Normative tables for reaching over, openings, access underneath and beam configurations are not included. Cases depending on those tables require verification against the applicable standard and do not produce a complete automatic result.
Learn is free: 29 articles in 5 learning paths, 25 diagrams, a glossary, original summaries, calculation tables and quizzes. Search and bookmarks help navigation. Examples can open a calculator, which requires Base or Unlimited. Sources and warnings are part of the content: consult the official standard for normative verification.
Reports and revisions
From the preview to the complete package.
- Complete the data: in the Report step check the declared title, machine, device and operator. Read the terms and the required declaration for the document. The PDFs are unvalidated technical drafts.
- Save the session: open it from Archive after saving and check repetitions, results, previews and revisions. Viewing remains free.
- Choose report access: a Single Report unlocks that session and all its repetitions for EUR 19.00 in Italy. Unlimited permits exports for any session while active. Apple shows the applicable price and terms before confirmation.
- Print or export: use “Print or export the PDF”, “Share the package” or “Export JSON/CSV”. In the iOS sharing sheet, choose the destination or compatible printer. The ZIP package can be large because it includes original recordings.
- Manage revisions: a new PDF from the same session is saved as a separate revision. Its digests and timestamps refer to that specific file. Retain earlier revisions when needed to reconstruct the work.
The package contains the available session files: recordings, PDFs and revisions, data, manifests, timestamp tokens and verification instructions. Review the file list and timestamp status before sharing. Purchasing a report does not include professional review or a signature.
Timestamps
Check the status before sharing.
StopTime requests RFC 3161 timestamps for the file digests specified by the workflow, including PDFs, manifests and original recordings. Providers receive digests and technical data, not complete file contents. See the privacy policy for recipients and processing details.
- Timestamp received: check which file and revision it covers. Keep the token and original file together.
- Pending or failed: check the connection and use Retry when available. A timestamp request is not proof that a timestamp was received.
- Sharing before completion: wait for the timestamp or share the available files. An exported copy does not update automatically. Export the package again after the request completes.
- Demonstration data: synthetic videos and timestamps labelled as test data do not provide timestamp evidence of a real test.
Timestamps and technical signatures concern file timing and integrity. They do not certify machine safety, operator identity or measurement correctness. A PDF without its corresponding token does not by itself enable independent timestamp verification.
In-app purchases
Four options with different features included.
| Option | Italian price | Included features |
|---|---|---|
| Learn and Archive | Free | Articles, diagrams, glossary, quizzes and viewing saved sessions and previews. |
| Base · Measure and Calculate | EUR 3.99/month EUR 39.90/year | Unlimited measurements and calculations; PDF calculator sheets included. Export of measurement reports available separately. |
| Single report | EUR 19.00 once | PDF, printing, ZIP, JSON and CSV for one session and all its repetitions. Reprints, later exports and revisions of that session are included. Does not unlock Measure or Calculate. |
| Unlimited | EUR 23.90/month EUR 229.99/year | All Base, plus printing and export of the reports of any session, without number limits, during the subscription. |
One measurement means one session. Single Report access includes all the session's repetitions and revisions. A new session requires separate report access or active Unlimited. The price covers software export, not professional review or certification.
With Unlimited, export before expiry. Sessions exported during the subscription remain unlocked on the device for reprints and further exports if you retain the Archive and associated entitlements. A session never exported requires active Unlimited or Single Report access. Viewing the Archive and saved previews remains free.
Trial and renewal. Monthly and annual Base plans include a 14-day free trial for eligible users, once per subscription group under Apple's rules. Unlimited has no free trial. Subscriptions renew automatically; manage or cancel in Settings › [your name] › Subscriptions › StopTime. Apple advises cancelling a free trial at least 24 hours before it ends. Apple cancellation guide.
Italian App Store prices checked on 1 October 2026, including VAT. The price, duration, trial eligibility and terms shown by Apple before confirmation apply. The app is free to download, with in-app purchases.
A pending payment does not unlock access. If Apple cannot charge a renewal, check your subscription status; no additional access period is guaranteed. Revocations or refunds may remove the affected entitlements.
Restore and backup
Purchases and archived data are separate.
Subscriptions: sign in to the same Apple Account used for the purchase, connect to the network, and use "Restore purchases" in the app. The restore verifies the available rights, but does not recreate deleted videos, reports, or sessions.
Single Report: access is linked to a specific session. On iOS 18 or later, the app can retrieve available completed purchases from Apple's history and associate them with the saved session. On iOS 17, restoration may depend on retaining local entitlements in Keychain; restoration after reinstalling or changing phone is not guaranteed.
Sessions exported with Unlimited: access after expiry is stored locally. Apple's subscription history alone cannot reconstruct which sessions were exported. Retain the Archive and Keychain data.
- Before replacing or resetting your iPhone, create a complete backup of your device; for a computer backup, use the encrypted backup option and keep the password secure. Apple Guide to Encrypted Backups.
- Also keep exported copies of the reports and packages you need, when you have the right to export them. A document ZIP is not a complete backup of the app and does not promise a reimport feature.
- After the transfer, check sessions, recordings, previews, and access to exports on the new phone before deleting the old storage.
App documents are not displayed as a freely browsable folder in Files or in Finder file sharing. Use the app's export actions. If a right is missing, restore it and contact support before purchasing again.
Frequently asked questions
Quick answers.
The camera does not offer the 240 fps: what do I check?
Check device compatibility and the available format, close other apps using the camera, and try again when the iPhone is not overheating. If the issue persists, send StopTime support the model, iOS version and displayed message. Do not force an unavailable option.
The analysis declares the measure invalid: why?
Both triggering and stopping events must be identifiable. Check warnings, selected regions, lighting, noise and the length of the stationary period at the end. Do not confirm an event just to pass a check: correct the conditions and repeat the test.
Why does the value of the session exceed that of a repetition?
Each repetition adds uncertainty U to the measured time. The session value also accounts for repetitions and the selected edition's criterion. The 2024 calculation includes a statistical criterion and flags insufficient samples. Check the summary and assumptions before using the value.
Can I use the acoustic trigger with any stop?
No. Check that the selected trigger represents the event in the stopping chain you intend to measure. Removing power from a module may introduce delays different from triggering its safety input or outputs. Read the trigger conditions and parameters in the app.
What can I use for free?
Learn and access the archive with the already saved previews. Measurement and Calculation require Base or Unlimited, or the currently active Base trial. Measurement reports are exported with a single or Unlimited unlock; calculator PDFs are included in Base.
Are the 19 euros for every repetition or reprint?
EUR 19.00 covers one measurement session, including all repetitions. You do not pay again to print, export or revise the same unlocked session, provided its Archive data and entitlements are retained. A new session requires separate report access.
Unlimited retains the right to export after the expiration date?
Yes, for sessions exported while Unlimited was active, with unlocking retained on the device. Sessions never exported require a new active period or Single Report. Before changing your iPhone, read the Backup and recovery guide.
Apple shows a pending purchase, or access is still locked. Should I purchase again?
Do not repeat the purchase immediately. Wait for the Apple result, check connection and Apple Account, and use Restore Purchases. The report will only unlock with a verified purchase. If there is still a problem, contact support by providing session and message; do not send passwords or card details.
How do I cancel or request a refund?
Manage StopTime in Settings › [your name] › Subscriptions. For the free trial cancel at least 24 hours before the end, according to the Apple guide.
For refunds use reportaproblem.apple.com: Apple assesses the request.
A timestamp is still pending. Can I share the report?
Check the options in the app. You may wait or share available files, but a missing timestamp is not confirmed. Export the package again when the request completes: previously shared copies do not update. Guide to timestamps.
Is the report a certificate or a professional signature?
No. It is an unvalidated technical draft. The operator is declared, not identified through a qualified-signature procedure. Digests, technical signatures and timestamps do not replace independent professional verification. Purchasing report access unlocks the software feature only.
Can I recover the archive only by restoring the purchases?
No. Apple restoration applies to purchases, not test files. Keep a complete backup of the device and verify the transfer; for individual reports and unlocked sessions with Unlimited, the limits described in Restore and backup.
Still have questions?
Write to us, we will reply.
Our support team understands machinery, light curtains and the standard.