Traceable 90225-35 Four-Channel Clock Timer with NIST-Traceable Calibration

Overview

The Traceable® 90225-35 Four-Channel Clock Timer is a laboratory-grade timing instrument engineered for precision, repeatability, and multi-task synchronization in regulated scientific environments. Designed according to ANSI/NCSL Z540-1 and ISO/IEC 17025 principles, it delivers NIST-traceable timekeeping across four independent channels—each fully programmable for countdown, stopwatch, or real-time clock operation. Unlike consumer-grade timers, this device employs quartz crystal oscillators stabilized for long-term drift control (<±0.01% over 30 days), ensuring compliance with GLP, GMP, and FDA 21 CFR Part 11 requirements for audit-ready time-stamped event logging. Its primary function is to support time-critical protocols including reaction monitoring, incubation cycles, titration endpoints, sterilization validation, and QC hold-time verification.

Key Features

• Four fully isolated timing channels—each configurable as independent countdown timer, elapsed-time stopwatch, or synchronized 12/24-hour clock
• Large-format LED display with 19 mm digit height for unambiguous visibility up to 10 meters under standard lab lighting conditions
• One-touch recall of previously set countdown values—enables rapid re-execution without manual re-entry
• High-intensity audible alarm (≥85 dB at 1 m) with 60-second auto-shutoff and immediate manual mute capability via front-panel button
• Integrated mounting system: includes adjustable bench stand, adhesive-backed wall bracket, and ferromagnetic rear plate for secure attachment to stainless steel surfaces
• Factory-calibrated with individual NIST-traceable Certificate of Calibration (Report No. prefixed “TR-”), documenting measurement uncertainty, environmental conditions, and traceability chain to NIST SRM 1010c

Sample Compatibility & Compliance

The 90225-35 imposes no sample interaction—its function is purely temporal reference generation and user notification. It is compatible with all laboratory workflows requiring concurrent time tracking: microbiological growth monitoring, enzymatic assay kinetics, thermal stability studies, and chromatographic run scheduling. The device meets IEC 61000-6-3 (EMC emissions) and IEC 61000-6-2 (immunity) standards. Its calibration documentation satisfies ISO 17025 clause 6.5.2 for measurement traceability and supports internal audit requirements under 21 CFR Part 11 §11.10(b) for electronic records where time stamps are critical data elements.

Software & Data Management

This is a standalone hardware timer with no embedded firmware update capability or USB/Bluetooth connectivity. All configuration and operation occur via tactile membrane buttons; no software installation or driver dependency is required. Time logs are not stored electronically—however, the NIST-traceable certificate provides permanent, paper-based evidence of calibration status valid for 12 months from issuance date. For laboratories implementing electronic lab notebooks (ELNs) or LIMS, the timer’s visual and audible outputs serve as human-verified time anchors for manual entry or automated camera-based timestamp capture (e.g., via time-lapse imaging systems).

Applications

• Pharmaceutical QC labs: Monitoring dissolution test durations, filter integrity hold times, and environmental chamber exposure periods
• Clinical diagnostics: Tracking reagent stability windows, ELISA incubation intervals, and centrifuge rotor run times
• Academic research: Synchronizing multi-step synthesis protocols, electrophoresis runs, and cell culture passaging schedules
• Food safety testing: Enforcing AOAC-defined holding times for enrichment broths and plating delays
• Materials testing: Coordinating ASTM D638 tensile test specimen conditioning periods and cure cycle verification

FAQ

Is the calibration certificate issued by an ISO/IEC 17025-accredited laboratory?
Yes—the certificate is provided by Cole-Parmer’s accredited metrology lab (A2LA Certificate No. 2391.01), with full uncertainty budgeting per ILAC P14:01/2013.
Can the timer be used in a cleanroom environment?
Yes—it contains no moving parts, generates no particulates, and its housing meets ISO Class 5 compatibility when mounted using the supplied non-shedding adhesive bracket.
What is the battery life under continuous operation?
With alkaline AA batteries (included), typical service life exceeds 18 months at 25°C ambient; low-battery indicator activates 72 hours prior to cutoff.
Does the device support external trigger input or relay output?
No—this model is manually operated only and does not feature TTL, dry-contact, or serial interfaces.
How often must recalibration be performed?
Annual recalibration is recommended per manufacturer guidelines and aligns with ISO/IEC 17025 clause 7.8.1 for maintaining measurement confidence; interval may be extended based on risk assessment per your lab’s QMS.