Monitoring Conditions for Optimum Lab Instrument Performance

By Chris Wetzel, MLS (ASCP), Laboratory Specialist

Chris Wetzel is involved with all facets of ACHC Clinical Laboratory Accreditation, including surveying and the development of standards. She also oversees client proficiency testing, CMS reporting, and educational webinars.

Posted: March 2, 2026

Laboratory instrument manufacturers set environmental requirements, such as temperature and humidity, to ensure their instruments perform properly. Monitoring of these environmental conditions is required under ACHC Standard 06.02.01 and CLIA Standards §493.1252(b)(1-4), §493.1282(b)(3).

This ACHC Standard is frequently cited as a deficiency during Clinical Laboratory Accreditation surveys. Compliance depends on accurate measurement and documentation of essential conditions, including evidence of corrective actions when conditions fall out of range.

Let’s take a close look at the standard and its required elements.

06.02.01 Essential Conditions

The laboratory must define criteria for those conditions that are essential for proper storage of reagents and specimens, accurate and reliable test system operation, and test result reporting. The criteria must be consistent with the manufacturer’s instructions, if provided. These conditions must be monitored and documented and, if applicable, include the following:

• Water quality.
• Temperature.
• Humidity.
• Protection of equipment and instruments from fluctuations and interruptions in electrical current that adversely affect patient test results and test reports.

Temperature and humidity

Survey findings often focus on issues with environmental temperature and/or humidity. The required elements of the standard provide additional details related to monitoring and documenting these conditions. For example, temperature-controlled spaces, equipment, and instruments must be monitored, and results documented, for acceptable temperature ranges.

Corrective action is needed when acceptable temperature ranges are exceeded.

Continuous monitoring of temperatures by a recording thermograph is acceptable, provided the data and time of use are annotated. Charts must be retained to document that temperatures were within the limits established by the laboratory.

In lieu of manual temperature recording, it is acceptable for the instrument to maintain and monitor temperatures internally, provided test results are flagged or not generated when the temperature range for test performance is exceeded.

Best practices

Your laboratory should review all operators’ manuals to determine the manufacturers’ requirements for temperature and humidity necessary for optimum instrument performance.

Create a chart (see example below) that lists each instrument’s temperature and humidity requirements, grouped by laboratory space. Highlight the most restrictive range and use that as the required range for that area. You may want to add any room temperature-dependent reagents stored in these areas to the chart to ensure that they remain within the appropriate range.

Sample chart

Use the right tools

Accuracy of the tools used to measure temperature and humidity is critical to achieving reliable results.

Other required elements of the standard specify that thermometers and hygrometers should be standard devices of known accuracy (certified to meet NIST Standards or traceable to NIST Standards) to monitor temperatures

(Thermometers and hygrometers must be recalibrated, recertified, or replaced before the date the guarantee of calibration expires, or they are subject to requirements for noncertified thermometers. All noncertified thermometers and hygrometers in use must be checked against an appropriate thermometric standard device before initial use, as defined by laboratory policy.)

Corrective actions must be documented when the temperature or humidity falls outside the established ranges.

Summary

Your clinical laboratory must define appropriate temperature and humidity ranges in accordance with instrument manufacturers’ requirements. Temperature and humidity records should be retained for at least two years. Thermometer and hygrometer certificates and/or calibration records should also be retained for a minimum of two years.

—
Read more articles about Clinical Laboratory Accreditation here.