A humidity datalogger supports ISO 17025 laboratory accreditation by providing documented, traceable records of environmental conditions in testing and calibration spaces. Clause 6.4 of the standard requires laboratories to monitor, control, and record conditions that could influence results, and a calibrated humidity datalogger is a practical tool for meeting that obligation. The sections below cover what to monitor, which device specifications matter, and how to manage records during an audit.
What environmental conditions does ISO 17025 require laboratories to monitor?
ISO 17025 requires laboratories to monitor any environmental conditions that could affect the validity of test or calibration results. In practice, this most commonly means temperature and relative humidity, though other factors such as air pressure, vibration, and contamination may also apply depending on the work being performed.
The standard does not prescribe a single set of acceptable ranges for every laboratory. Instead, it places the responsibility on the laboratory itself to define which conditions are relevant to its activities and to establish acceptable limits for those conditions. For most analytical and calibration labs, this means setting upper and lower thresholds for both temperature and humidity and recording whether those thresholds are maintained consistently over time.
Humidity is particularly important in environments where moisture-sensitive materials, hygroscopic substances, or precision instruments are in use. High humidity can cause condensation on sensitive equipment, affect the mass of samples, or accelerate corrosion. Low humidity can introduce static electricity that interferes with measurements. Either extreme can compromise result validity, which is exactly what ISO 17025 is designed to prevent.
How does a humidity datalogger help meet ISO 17025 clause 6.4 requirements?
A humidity datalogger helps meet ISO 17025 clause 6.4 requirements by automatically capturing and storing timestamped environmental readings at defined intervals, creating the continuous documented record the standard demands. Rather than relying on manual spot checks, a datalogger provides objective evidence that conditions were within acceptable limits throughout a measurement period.
Clause 6.4 specifically states that laboratories shall monitor, control, and record environmental conditions in accordance with relevant specifications, methods, and procedures. A datalogger addresses all three verbs in that sentence. It monitors continuously, it supports control by alerting staff when conditions drift outside set limits, and it records every data point in a retrievable format.
For auditors, this matters because it removes ambiguity. A logbook entry made once per shift leaves large gaps in the record. A datalogger logging every few minutes or every hour provides a complete picture that an assessor can review with confidence. This is especially relevant during accreditation assessments, where the quality of environmental monitoring documentation is scrutinized closely.
What specifications should a humidity datalogger have for accredited lab use?
A humidity datalogger for accredited laboratory use should have a calibrated sensor with a known and documented measurement uncertainty, a logging interval that matches the sensitivity of the work being performed, sufficient memory for continuous long-term recording, and a clear data export function that produces audit-ready reports.
The most critical specification is calibration traceability. ISO 17025 itself is a standard for calibration and testing laboratories, so it would be inconsistent to monitor environmental conditions with a device whose accuracy cannot be traced to a national or international measurement standard. Any datalogger used in this context should come with a calibration certificate that references an accredited calibration body and states the measurement uncertainty at the humidity ranges relevant to your lab.
Beyond calibration, consider the following practical specifications:
- Measurement range: Ensure the sensor covers the full range of conditions your lab may experience, not just the target operating range.
- Resolution and accuracy: For most lab environments, a resolution of 0.1% relative humidity and accuracy within ±2 to 3% RH is adequate, though tighter tolerances may be needed for highly sensitive work.
- Logging interval: Shorter intervals capture transient fluctuations that longer intervals would miss. A one-minute or five-minute interval is common for lab use.
- Data retrieval method: The device should allow easy export of complete records without data loss or manipulation during transfer.
- Battery reliability: Continuous monitoring requires a battery that performs consistently over extended periods. Paper-based loggers from Tapp, for example, use a lithium-free battery design that avoids the voltage degradation common in single-use electronic loggers, making them more predictable over the full logging duration. The world’s first paper-based datalogger takes this approach to deliver consistent performance throughout the monitoring period.
How should humidity datalogger records be managed during an ISO 17025 audit?
During an ISO 17025 audit, humidity datalogger records should be organized, complete, and immediately retrievable. Auditors will look for evidence that monitoring was continuous, that any out-of-range conditions were identified and acted upon, and that the datalogger itself was calibrated within a valid period at the time the records were created.
Good record management starts before the audit. Establish a routine for downloading and archiving data at regular intervals, and store records in a way that links them clearly to the time periods and laboratory areas they cover. Records should include the device identifier, its calibration status, the defined acceptable range, and any corrective actions taken when conditions exceeded that range.
During the assessment itself, be prepared to demonstrate the following:
- The datalogger’s current calibration certificate, including measurement uncertainty and the accredited body that issued it.
- A complete, unbroken log covering the period under review, with no unexplained gaps.
- Evidence that out-of-range events were recorded, investigated, and resolved.
- The procedure your laboratory follows for monitoring, including defined acceptable limits and review frequency.
One practical tip is to retain records for at least as long as your laboratory’s own retention policy requires, and to keep calibration certificates alongside the data files they relate to. This makes cross-referencing straightforward when an auditor asks to verify that the device was in calibration at a specific point in time.
How paper-based dataloggers help with humidity and temperature monitoring in lab environments
For laboratories looking to simplify environmental monitoring without adding infrastructure complexity, paper-based dataloggers offer a practical alternative to traditional electronic devices. Tapp’s paper-based dataloggers are designed to log temperature and humidity conditions passively during use, and data can be retrieved instantly with a smartphone tap using NFC technology, with no app required.
Key advantages for lab monitoring use cases include:
- No USB connections or dedicated software: Data is accessed with any NFC-enabled smartphone and automatically uploaded to the cloud, making retrieval straightforward for any team member.
- Lithium-free battery: Unlike single-use electronic loggers, which rely on lithium cells that can suffer voltage drop over time, the lithium-free battery in paper-based loggers delivers consistent performance across the full logging period, reducing the risk of missed readings.
- Sustainable disposal: Electronic dataloggers require e-waste disposal. Paper-based loggers are recyclable through standard paper waste streams globally, which supports laboratory sustainability goals without adding a separate disposal process.
- Cloud-based records: Logged data is stored automatically, making it easy to retrieve complete records for audit purposes without manual file management.
If your laboratory is reviewing its environmental monitoring approach ahead of an accreditation assessment, explore Tapp’s paper-based dataloggers to see how a simpler, more sustainable option could fit your documentation and monitoring needs.
