Laboratory validation executed by Romuald Gawlik, CEO of ROGA Instruments. A calibrated function generator feeds a synchronized sine sweep into a split “T” connection, driving a certified Class 1 Sound Level Meter (Type 308) and FreqCheck running on an iPhone via the Plug.n.DAQ Lite / iSV1611 USB interface simultaneously.
Class 1 Tolerance Compliance: Tracks reference hardware within 0.1 dB to 0.2 dB, operating well inside the ±0.5 dB IEC 61672 Class 1 corridor across the audible spectrum.
Filter Execution: Direct mathematical processing of IEC dBA, dBC, and flat Linear (Lin-Z) weighting curves against unadulterated ADC voltage inputs.
Ballistic Integration: True 125 ms (Fast) and 1000 ms (Slow) exponential RMS time weighting matching physical laboratory meters.
Standard iOS core audio pipelines enforce aggressive low-frequency attenuation below 20 Hz. Operating in Pro Input Mode (PIM), FreqCheck bypasses internal audio filters to ingest raw transducer signals directly from the iSV1611 front end, maintaining linear spectral response and resolving signals down to 0.2 Hz using 32,768-point FFT computation.
CRYPTOGRAPHIC AUDIT TELEMETRY
Every test measurement generates an immutable, timestamped PDF report sealed with a SHA-256 cryptographic hash at the moment of capture. Test records embed verified metrology configuration snapshots (sample rate, ADC ceiling, sensor sensitivity, and channel assignment) for direct ingestion into ISO/IEC 17025 Laboratory Information Management Systems (LIMS).
Direct mechanical coupling: aligning digital signal processing with physical acoustic reference standards to maintain unbroken Class 1 traceability in field environments.
Field calibration: 94 dB / 114 dB reference tone locking via ROGA acoustic calibrator.
Accessible directly under Instrumentation Settings, FreqCheck locks onto continuous reference tones to compute precise transducer sensitivity offsets, verifying physical hardware integrity prior to active measurement runs:
Dual Reference Standards: Native locking for standard 94.0 dB (1 Pa) and 114.0 dB (10 Pa) acoustic levels at either 250 Hz or 1000 Hz.
Environmental Correction: Automatically calculates exact gain adjustments to compensate for local atmospheric pressure, temperature, and relative humidity.
Hardware-Agnostic Interface: Accommodates standard 1″, 1/2″, and 1/4″ Class 1 measurement microphones paired with UAC-2 digitizers.
Immutable Chain of Custody: Active calibration factors and date-time stamps are permanently hashed into exported ISO/IEC 17025 PDF audit reports.
Performing physical reference calibrations on-site ensures your complete hardware signal chain meets regulatory audit standards without reliance on fixed laboratory setups.
A purpose-built metrology program for small arms suppressor testing and blast overpressure criteria. Features automated peak-hold event counting, A-duration transient logging, and NIST-traceable cryptographic audit reporting for defense compliance.
Operating at clock rates up to 384 kHz, FreqCheck replaces multichannel oscilloscope racks and manual waveform stitching with automated, real-time edge processing. Transient pressure peaks are logged at hardware speed, paired with active transducer calibration factors, and cryptographically sealed into immutable PDF audit sheets:
MIL-STD-1474E & ASTM F2439: Small arms suppressor testing, blast overpressure limits, and impulse noise criteria.
ISO 10843 & ISO 1996: Impulsive noise measurement, industrial shock, and environmental blasting compliance.
SAE J211-1 & ISO 12017: Automotive restraint, airbag deployment, and high-g transient telemetry.
By automating threshold arming, peak detection, and Lavg integration natively on iOS, testing facilities eliminate thousands of dollars in legacy data acquisition overhead while maintaining field-grade metrology compliance.
Direct multi-modal DAQ processing: ingesting unadulterated voltage streams from standard industrial accelerometers into calibrated acceleration, velocity, and seismic telemetry.
Bench demonstration: Standard IEPE accelerometer coupled via ROGA K65 DAQ interface.
FreqCheck is engineered as an open, hardware-agnostic metrology architecture compatible with USB Audio Class (UAC-2) compliant digitizers, multi-channel DAQ interfaces, and charge amplifiers. Demonstrations conducted with ROGA hardware validate direct ingestion across the full DC-coupled spectrum (0.2 Hz to 192 kHz), bridging acoustic pressure and structural dynamics on standard iOS hardware:
Universal Sensor Compatibility: Ingests voltage metrics from standard IEPE (ICP®), piezoelectric, and piezoresistive accelerometers with configurable sensitivity coefficients (mV/g or mV/m·s²).
ISO 10816 & ISO 20816: Mechanical vibration severity evaluation, rotating machinery diagnostics, and bearing fault spectral analysis.
DIN 4150-3: Structural vibration evaluation in civil engineering, foundation stability, and infrastructure monitoring.
Sub-Hz Seismic Integrity: Preserves low-frequency structural resonance down to 0.20 Hz without OS-level high-pass degradation or phase shift.
Cryptographic Data Integrity: Generates tamper-evident SHA‑256 sealed PDF audit sheets recording sensor serials, gain stages, and calibration offsets for ISO/IEC 17025 LIMS ingestion.
Laboratories and field teams deploy existing Class 1 acoustic microphones or structural vibration transducers interchangeably—retaining their preferred transducer hardware while modernizing data capture and chain of custody.
SIGNAL ARCHITECTURE & INTERACTIVE FORENSICS
REAL-TIME FFT RESOLUTION & GHOST-TRACE SCRUBBER
Deterministic hardware handshaking, dynamic FFT binning, and interactive crosshair forensic analysis across audible, ultrasonic, and sub-audible bands.
Interactive HUD: Live fingertip scrubbing across active and frozen peak-hold envelopes.
FreqCheck bypasses standard consumer audio limits to run a deterministic, laboratory-grade signal chain directly on iOS. By commanding external ADC clocks up to 384 kHz and computing up to 65,536-point FFTs on device, the engine maintains sub-Hz spectral resolution and zero-drift baselines in real time:
Pro Input Mode (PIM): Completely disables iOS Automatic Gain Control (AGC) and noise gates. Unlocks discrete channel routing (Left Ch 1 / Right Ch 2), hardware clock locking (44.1 kHz to 384.0 kHz), and direct manual entry for sensor sensitivities (mV/Pa, mV/g) and ADC reference ceilings.
Interactive Ghost-Trace Scrubber: Unlike static spectrum analyzers, FreqCheck allows touch-directed crosshair tracking across live telemetry and frozen post-event envelopes—pinpointing precise center frequencies and amplitude peaks across 30 Hz to 192 kHz.
Real-Time Hardware DC Correction: Eliminates analog DC offset at the driver layer before FFT ingestion, delivering flat, reproducible spectral baselines without sacrificial high-pass brick-wall filters.
Universal UAC-2 Compliance: Connects directly with standard USB Audio Class digitizers, multi-channel DAQs, and charge amplifiers, accommodating standard 1″, 1/2″, and 1/4″ measurement transducers.
DEFENSIBLE CHAIN OF CUSTODY
ISO/IEC 17025 LIMS-READY EDGE AUDIT TELEMETRY
Conventional field testing relies on unverified CSV exports easily modified after the fact. FreqCheck replaces editable files with cryptographically sealed PDF audit records generated immediately upon test completion.
Each report captures the full metrology state—including transducer serial, calibration sensitivity, sample rate, and trigger threshold—sealed with an immutable SHA‑256 hash. These certified records feed directly into enterprise Laboratory Information Management Systems (LIMS), providing court- and audit-ready documentation without legacy dynamic signal analyzer (DSA) overhead.
RUN IDENTICAL LAB-GRADE ANALYSIS ON PAST RECORDINGS AS LIVE HARDWARE
Have field recordings or video files sitting on a drive? Import them directly into FreqCheck. By matching your original recording settings in Pro Input Mode (PIM), the engine generates the exact same Class 1 acoustic, vibration, and ballistic results as a live bench test.
In legal disputes, code enforcement cases, and failure analysis, past recordings are often dismissed because they lack formal calibration data. FreqCheck solves this by letting you import standard uncompressed audio (.WAV, .AIFF) or extracted video audio tracks, then applying its complete metrology pipeline retroactively.
Simply enter your original capture parameters in Pro Input Mode—sampling rate (up to 384 kHz), voltage ceiling, and sensor sensitivity (mV/Pa or mV/g). FreqCheck processes the file through the exact same mathematical engine used for live hardware:
Bit-for-Bit Live Parity: Applies full 65,536-point FFT resolution, standard IEC time weighting (Fast/Slow/Impulse), and dBA/dBC curves to match a real-time hardware run.
Sub-Hz & Shockwave Recovery: Re-interrogates archived recordings down to 0.20 Hz infrasound or re-evaluates ballistic transient peaks against MIL-STD-1474E standards without destructive filtering.
Interactive Scrubbing: Scrub through the entire recorded waveform using the crosshair tool to pinpoint developing spikes, harmonic distortion, or intermittent noise.
Cryptographic Proof: Converts unverified legacy files into tamper-evident, SHA‑256 hashed PDF audit reports accepted by courts, insurance adjusters, and LIMS databases.
Recordings from old cases or past field runs don't need to be redone—import the file, assign the calibration factors, and generate a certified audit report on the spot.
For clients operating under mutual NDA, we develop custom builds and proprietary signal algorithms tailored to specialized facility tolerances. Builds are provisioned privately and distributed directly to your organization’s Apple Business Manager (ABM) portal—bypassing the public App Store for air-gapped, zero-telemetry defense and cleanroom environments.
VERIFIED SIGNAL TELEMETRY & TECHNICAL ARCHITECTURE
A centralized, searchable archive for acoustic engineers, metrologists, and field technicians to cross-reference real-world captures and verify field data against collective benchmarks.
GENERAL SUPPORT, AI INTELLIGENCE & FORUM
Need help or want to talk metrology? Nyquist is your 24/7 support hub, intelligent guide, and collaborative community forum. Accessible via the persistent Nyquist button on any page or screen, it bridges instant automated assistance with peer discussions:
24/7 AI Guide & App Support: Get immediate answers for general inquiries, app navigation, subscription tiers, and step-by-step workflow setup.
Hardware, Cabling & Calibration: Interactive troubleshooting for USB DAQs, IEPE transducer coupling, channel mapping, and entering sensitivity factors (mV/Pa or mV/g).
Signal Mathematics & Metrology Standards: Expert assistance interpreting 384 kHz wideband data, FFT binning, MIL-STD-1474E impulse peaks, and ISO 17025 compliance rules.
Active Community Forum & Trace Vault: An open technical forum where field engineers and testing teams publish verified signal traces, debate test methodologies, and archive forensic cases (searchable by everyone; posting unlocked for Pro subscribers).
