Grant Squirrel SQ2040 Wi-Fi Data Acquisition Unit
| Brand | Grant |
|---|---|
| Origin | United Kingdom |
| Model | SQ2040 Wi-Fi |
| Analog Inputs | 16 differential or 32 single-ended (24-bit Sigma-Delta ADC) |
| Temperature Sensor Support | Thermocouples (K, R, B, T, S, C, N, J, D), RTDs (Pt100/Pt1000, 2-/3-/4-wire), thermistors |
| Voltage Range | ±0.075 V to ±25 V (differential/single-ended) |
| High-Voltage Inputs | 4–20 V, 4–40 V, 4–60 V |
| Current Input | –30 to 30 mA (with external 10 Ω shunt) |
| Resistance Range | 0–1250 Ω (2-wire) |
| Pulse Inputs | 4 channels (2 × 64 kHz fast, 2 × 100 Hz slow) |
| Digital/Event Inputs | 8 status or 1×8-bit binary |
| Sampling Rate | Up to 100 readings/sec on up to 4 channels (model-dependent) |
| Internal Memory | 128 MB (up to 14 million readings) |
| Communication | IEEE 802.11b Wi-Fi (2.4 GHz, WEP/WPA/WPA2), USB 1.1/2.0, RS-232 (auto-baud up to 115.2 kbps) |
| Power | 6 × AA alkaline batteries or 10–18 VDC (reverse polarity & overvoltage protected) |
| Operating Environment | –30 to +65 °C, ≤95% RH non-condensing |
| Display | 128 × 64 pixel graphical LCD with 4-button keypad |
| Weight | 1.2 kg |
| Enclosure | ABS plastic |
| Compliance | CE, RoHS, FCC Class B |
Overview
The Grant Squirrel SQ2040 Wi-Fi Data Acquisition Unit is a high-fidelity, field-deployable data logger engineered for precision multi-sensor monitoring in industrial process validation, environmental research, pharmaceutical stability testing, and academic instrumentation labs. Built upon a dual-processor architecture with multiple 24-bit sigma-delta analog-to-digital converters (ADCs), the SQ2040 Wi-Fi delivers true synchronous sampling across mixed-signal inputs—enabling simultaneous high-speed capture of transient events (e.g., pressure spikes or valve actuation) alongside slower-varying parameters (e.g., ambient temperature or humidity). Its integrated IEEE 802.11b Wi-Fi interface operates in infrastructure mode with enterprise-grade security (WEP, WPA, and WPA2/802.11i), allowing secure remote configuration, real-time telemetry streaming, and scheduled data retrieval over TCP/IP networks—without requiring local PC presence. The unit supports deterministic time-stamping per reading using an internal temperature-compensated real-time clock (RTC) compliant with ISO/IEC 17025 traceability requirements for calibration records.
Key Features
- True synchronous multi-channel acquisition: Independent sample rate assignment per channel (1–100 Hz), enabling dynamic parameter correlation without aliasing artifacts.
- Universal analog input architecture: Configurable per channel for voltage (±0.075 V to ±25 V), current (–30 to 30 mA with 10 Ω shunt), resistance (0–300 kΩ, 2-wire; 0–4 kΩ, 3-/4-wire), thermocouple (K, R, B, T, S, C, N, J, D), RTD (Pt100/Pt1000), and thermistor inputs—all calibrated at 25 °C with ±0.05% of reading + 0.025% of range accuracy.
- Dedicated high-voltage inputs (4–60 V DC) and pulse inputs (2 × 64 kHz, 2 × 100 Hz) for motor control feedback, flow meter pulses, or digital event logging.
- Eight digital status inputs or 1×8-bit binary encoding for discrete system state monitoring (e.g., door open/closed, pump on/off).
- Four open-drain FET outputs (18 V, 0.1 A) programmable as alarms or control signals, supporting fail-safe interlocks in regulated environments.
- Onboard computational engine: Up to 16 derived (virtual) channels using arithmetic, logarithmic (log, ln), square root, and linearization functions applied to raw sensor inputs—reducing post-processing overhead.
- Non-volatile internal memory (128 MB) stores up to 14 million timestamped readings; optional MMC/SD card (up to 1 GB) enables offline archival and configuration portability.
Sample Compatibility & Compliance
The SQ2040 Wi-Fi accommodates sensors conforming to ASTM E2877-22 (temperature mapping), ISO 14644-3 (cleanroom environmental monitoring), and USP (analytical instrument qualification). Its thermocouple and RTD input circuitry meets IEC 60584-1 and IEC 60751 tolerance classes, respectively. The device operates within GLP/GMP-aligned workflows through audit-trail-capable configuration management: all setup changes—including channel scaling, alarm thresholds, and sampling schedules—are stored with timestamps and user identifiers when configured via SquirrelView Plus. Firmware and configuration files are digitally signed to prevent unauthorized modification, supporting FDA 21 CFR Part 11 compliance when deployed with validated IT infrastructure.
Software & Data Management
SquirrelView (included) provides full configuration export/import, real-time waveform visualization, and CSV/Excel data export with metadata (channel name, units, calibration date, sensor ID). SquirrelView Plus (optional) adds statistical process control (SPC) charting, automated report generation (PDF/HTML), and SQL database integration for LIMS synchronization. All communication—Wi-Fi, USB, or RS-232—is handled via standardized Modbus TCP/RTU and native TCP socket protocols, enabling seamless integration into SCADA, MES, or cloud-based IIoT platforms (e.g., AWS IoT Core, Azure IoT Hub). Remote firmware updates are performed over encrypted Wi-Fi sessions with checksum verification.
Applications
- Pharmaceutical cold chain validation: Continuous monitoring of storage and transport conditions per EU GDP Annex 9 and WHO TRS 961.
- Energy efficiency audits: Simultaneous logging of HVAC supply/return temperatures, static pressure, and fan power consumption.
- Materials testing labs: Correlating thermal expansion (RTD), strain (bridge output), and acoustic emission (pulse count) during mechanical fatigue cycles.
- Food safety HACCP plans: Real-time verification of cook/chill hold times and temperatures across multiple zones.
- Academic physics experiments: Capturing transient electromagnetic induction waveforms while concurrently logging ambient barometric pressure and relative humidity.
FAQ
Does the SQ2040 Wi-Fi support TLS-encrypted Wi-Fi connections?
No—it implements WPA2-PSK and WPA3-SAE (via firmware update) but does not support certificate-based TLS handshaking. For high-security deployments, it is recommended to operate within a segregated VLAN with firewall-enforced egress filtering.
Can I perform real-time math operations on live sensor data without exporting?
Yes—up to 16 virtual channels can be defined with expressions such as “(Ch1 – Ch2) / 1000” or “sqrt(Ch3 * Ch4)” and logged alongside physical inputs at full resolution.
Is the internal clock traceable to UTC via NTP?
No—the RTC is temperature-compensated but not NTP-synchronized. Time alignment must be performed manually or via scheduled USB/RS-232 sync before deployment; timestamp drift is <±2 seconds/month at 25 °C.
What is the maximum sustainable sampling rate across all analog channels?
The unit sustains 100 Hz on up to four channels simultaneously (SQ2040-4F16 model); remaining analog channels default to lower rates (1–10 Hz) unless explicitly assigned higher values—subject to total memory bandwidth constraints.
Are calibration certificates provided with the instrument?
Grant supplies factory calibration data (as-received accuracy verification) with each unit. UKAS-accredited calibration is available as an optional service, traceable to NPL standards and documented per ISO/IEC 17025.
