Digi-Sense Traceable® Dual-Channel and Single-Channel Big-Digit LED Timers with NIST-Traceable Calibration Certificate

Overview

The Digi-Sense Traceable® Big-Digit LED Timer series (Models 94461-15 and 94461-16) is a precision-engineered laboratory timing solution designed for environments where traceability, visibility, and operational reliability are critical. These timers implement quartz-crystal-based timekeeping with digital logic control to deliver high reproducibility in both countdown and elapsed-time modes. The dual-channel variant (94461-15) supports independent timing sequences with distinct visual and auditory alerts per channel—enabling concurrent monitoring of two separate procedures without cross-interference. Both models feature large-digit LCD displays (0.625″ or 1″ character height) optimized for legibility across laboratory workspaces, including fume hoods, biosafety cabinets, and shared instrumentation benches. Each unit ships with an individual NIST-traceable calibration certificate issued by an ISO/IEC 17025-accredited calibration laboratory, confirming conformance to defined accuracy specifications (±0.01% over full timing range) at time of shipment.

Key Features

• Large-format LCD display with high-contrast digits visible from distances up to 3 meters
• NIST-traceable calibration certificate included—valid upon receipt; no additional user calibration required
• Dual-channel model (94461-15): Independent start/stop controls, unique alarm tones, and dedicated red/green LED indicators per channel
• Intelligent alert system: Green LED flashes once per second during final 10 seconds; red LED pulses rapidly at zero, accompanied by audible alarm
• Three programmable countdown presets stored in non-volatile memory for rapid recall of frequently used intervals
• Adjustable audio alarm with three volume levels (High/Low/Off) to accommodate noise-sensitive or hearing-impaired environments
• Post-zero elapsed-time counter: Automatically switches to upward counting mode after reaching zero, supporting post-procedure timing workflows
• Multi-modal mounting: Integrated magnetic backing, fold-out easel stand, and top-mounted hanging loop for flexible placement on metal surfaces, countertops, or wall-mounted fixtures

Sample Compatibility & Compliance

These timers are not sample-contact devices and impose no physical or chemical constraints on experimental materials. Their design ensures compatibility with standard laboratory environmental conditions: operating temperature range 10–40 °C, relative humidity ≤80% non-condensing. As standalone timing instruments, they comply with electromagnetic compatibility (EMC) requirements per FCC Part 15 Class B and CE directives. Critically, the included NIST-traceable calibration supports adherence to regulatory frameworks requiring documented measurement assurance—including ISO/IEC 17025, FDA 21 CFR Part 11 (when integrated into electronic lab notebooks), cGMP Annex 11, CLIA, CAP, Joint Commission standards, and VFC program requirements. The calibration report documents uncertainty budgets, reference standards (NIST SRM traceability path), and environmental conditions at time of verification.

Software & Data Management

No external software or drivers are required for operation. All configuration—including preset storage, alarm volume selection, and channel activation—is performed via intuitive front-panel push-button interface. Time data remains fully accessible through the LCD display only; no proprietary file formats, cloud connectivity, or firmware updates are implemented. This architecture ensures deterministic behavior, eliminates cybersecurity attack vectors, and satisfies audit requirements for systems used in regulated quality control (QC) and good manufacturing practice (GMP) environments. The calibration certificate contains full metrological data: as-found/as-left values, measurement uncertainty (k=2), date of calibration, and laboratory accreditation number—enabling direct integration into laboratory quality management systems (QMS) for instrument qualification records.

Applications

• Standardized incubation and reaction timing in microbiology, molecular biology, and cell culture workflows
• Controlled drying, curing, or heating cycles in materials science and polymer processing labs
• Calibration interval tracking and equipment maintenance scheduling
• Training and SOP compliance monitoring in GLP/GMP training laboratories
• Parallel process coordination—e.g., simultaneous centrifugation, spectrophotometric readings, or titration endpoints across multiple stations
• Time-critical safety protocols: chemical exposure limits, UV sterilization cycles, and biosafety cabinet decontamination sequences

FAQ

Is the NIST-traceable calibration certificate sufficient for ISO/IEC 17025-compliant laboratories?
Yes—the certificate is issued by an ILAC-MRA signatory laboratory accredited to ISO/IEC 17025, with documented uncertainty budgets and explicit linkage to NIST reference standards.
Can the timer be used in environments requiring ATEX or IECEx certification?
No—this device lacks intrinsic safety certification and is intended for general laboratory use only.
Does the timer support synchronization with external clock sources or network time protocol (NTP)?
No—it operates autonomously using internal quartz timing circuitry; no network interfaces or external sync capability are provided.
What is the expected battery life under typical usage conditions?
With two fresh AAA alkaline cells, operational life exceeds 12 months under average daily use (≤2 hours active timing per day).
Are replacement calibration certificates available if the original is lost?
Yes—certificates can be reissued upon request with proof of purchase and serial number verification, subject to laboratory archival retention policies (typically 5 years).