US Environmental Protection Agency Office of Pesticide Programs SOP for Maintenance and Calibration of Thermometers and Thermometer/Hygrometers Date Revised: 7-14-11 ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 1 of 10 EPA/OPP MICROBIOLOGY LABORATORY ESC, Ft. Meade, MD Standard Operating Procedure for Maintenance and Calibration of Thermometers and Thermometer/Hygrometers SOP Number: EQ-02-06 Date Revised: 07-14-11 Initiated By: Date: / / Print Name: Technical Review: Date: / / Print Name: Technical Staff QA Review: Date: / / Print Name: QA Officer Approved By: Date: / / Print Name: Branch Chief Effective Date: / / Controlled Copy No.: Withdrawn By: Date: / / ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 2 of 10 TABLE OF CONTENTS Contents Page Number 1.0 SCOPE AND APPLICATION 3 2.0 DEFINITIONS 3 3.0 HEALTH AND SAFETY 4 4.0 CAUTIONS 4 5.0 INTERFERENCES 4 6.0 PERSONNEL QUALIFICATIONS 4 7.0 SPECIAL APPARATUS AND MATERIALS 4 8.0 INSTRUMENT OR METHOD CALIBRATION 5 9.0 SAMPLE HANDLING AND STORAGE 5 10.0 PROCEDURE AND ANALYSIS 5 11.0 DATA ANALYSIS/CALCULATIONS 6 12.0 DATA MANAGEMENT/RECORDS MANAGEMENT 7 13.0 QUALITY CONTROL 7 14.0 NONCONFORMANCE AND CORRECTIVE ACTION 8 15.0 REFERENCES 8 16.0 FORMS AND DATA SHEETS 8 ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 3 of 10 1.0 SCOPE AND APPLICATION: 1.1 This protocol describes the thermometers and thermometer/hygrometers in use in the laboratory, calibration requirements for ISO 17025 accredited verification thermometer and the procedure to point-check the accuracy of thermometers (i.e., liquid in glass and mercury in teflon-coated glass) used to measure the temperature of autoclaves, water baths, incubators, refrigerators, and freezers. 1.2 See section 2.1 for calibration requirements for ISO 17025 accredited vendor- calibrated liquid in glass thermometers, mercury thermometers, digital thermometers, and thermometer/hygrometers. 1.3 The laboratory utilizes an Environmental Monitoring and Alarm System (EMAS; see SOP QC-05, Monitoring Environmental Parameters) to collect environmental data electronically for incubators, refrigerators, freezers, laboratories, and sample storage rooms. In the event that EMAS is not working, the appropriate thermometers will be point-checked against an ISO 17025 accredited verification liquid in glass thermometer and employed to measure the temperature of incubators, refrigerators, and freezers. ISO 17025 accredited vendor-calibrated thermometer/hygrometers are used to monitor the temperature/humidity of laboratories and sample storage areas. 2.0 DEFINITIONS: 2.1 ISO 17025 accredited verification thermometer - a thermometer (liquid in glass, mercury in teflon-coated glass, digital, or digital thermometer/hygrometer) that has been calibrated by a recognized ISO 17025 accredited vendor. The calibration certificate must contain the stamp of the accrediting body (e.g., A2LA) and the calibration vendor certificate number. 2.1.1 Representative liquid in glass and mercury in teflon-coated glass ISO 17025 accredited verification thermometers are used to point-check the accuracy of other laboratory thermometers of a similar type. 2.1.2 All digital thermometers and thermometer/hygrometers used in the laboratory are calibrated annually by an ISO 17025 accredited vendor. 2.2 Correction Factor = the difference in the vendor-certified ISO 17025 accredited verification thermometer and the Observed Temperature measured by the thermometer to be point-checked. This is calculated and reported during the annual certification of the thermometers. ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 4 of 10 3.0 HEALTH AND SAFETY: 3.1 Teflon-coated mercury in glass thermometers are permissible in the laboratory. Non-coated mercury thermometers are not permissible. The teflon coating reduces the likelihood that mercury will be spilled in the event that the thermometer is broken. If a teflon-coated mercury in glass thermometer (section 7.2) breaks (teflon remains intact), place the thermometer in the chemical waste bin in the fume hood in B209 for disposal. If the integrity of the teflon coating is questionable, call the SHEM manager (or contact security at extension 52800 if SHEM manager cannot be reached) immediately for assistance. 4.0 CAUTIONS: 4.1 Analysts are not to attempt to clean up any spills of mercury. 4.2 Discard mercury thermometers appropriately. 5.0 INTERFERENCES: 5.1 Allow the thermometer to equilibrate with the solutions before taking the temperature reading. 6.0 PERSONNEL QUALIFICATIONS: 6.1 Personnel are required to be knowledgeable of the procedures in this SOP. Documentation of training and familiarization with this SOP can be found in the training file for each employee. 7.0 SPECIAL APPARATUS AND MATERIALS: To determine which thermometers are currently in use in the laboratory, refer to the Point-Check Calibration of Laboratory Thermometers Record Book. 7.1 ISO 17025 accredited verification thermometer. The ISO 17025 accredited verification thermometers are certified annually (see section 2.1) by an ISO 17025 accredited vendor. Representative liquid and mercury in teflon-coated glass ISO 17025 accredited verification thermometers are used to verify the accuracy of like thermometers specified in sections 7.2 and 7.5. 7.2 Kessler maximum registration thermometers (ERTCO, mercury- containing/teflon-coated) are used to verify autoclave temperatures. One representative thermometer is certified annually by an ISO 17025 accredited ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 5 of 10 vendor (see section 2.1 for certification requirements) and is used to check the accuracy of the remaining thermometers. 7.3 Digital thermometers for freezers. All digital thermometers are certified annually by an ISO 17025 accredited vendor. See section 2.1 for certification requirements. 7.4 Thermometer/hygrometers are used to measure temperature and humidity of laboratory rooms, incubators, and other spaces. All thermometer/hygrometers thermometers are certified annually by an ISO 17025 accredited vendor. See section 2.1 for certification requirements. 7.5 Thermometers (i.e., liquid in glass) used to measure the temperature of water baths, incubators, refrigerators, and freezers, including FRIO-Temp Precision Thermometers. 8.0 INSTRUMENT OR METHOD CALIBRATION: 8.1 Thermometers, liquid in glass and mercury in teflon-coated glass, are checked for accuracy using an ISO 17025 accredited verification thermometer. 9.0 SAMPLE HANDLING AND STORAGE: Not applicable 10.0 PROCEDURE AND ANALYSIS: 10.1 Annual thermometer calibration reports (see section 2.1 for certificate requirements) for thermometers certified by ISO 17025 accredited vendors are stored in the Thermometer and Hygrometer Calibration Certificates notebook. 10.2 Once a year, all of the thermometers falling under sections 7.2 and 7.5 of this SOP are checked at operating temperatures against a similar type thermometer certified by an ISO 17025 accredited vendor. 10.3 To point-check the accuracy of FRIO-Temp Precision Thermometers, place a flask of de-ionized water or ethanol next to the thermometer in the incubator, refrigerator, or freezer. Place the liquid in glass ISO 17025 accredited verification thermometer into the flask of de-ionized water or ethanol. Once the de-ionized water or ethanol has reached the temperature of interest, conduct the accuracy check. The ISO 17025 accredited verification thermometer must be suspended in the liquid in the flask, not resting on the bottom of the flask. 10.4 A water bath is used, where applicable, to check the temperature of the thermometers (excluding the FRIO-Temp Precision Thermometers) by ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 6 of 10 simultaneous immersion of the ISO 17025 accredited verification thermometer and the thermometer to be calibrated into the water bath at the temperature of interest. Otherwise, point-checks are taken by simultaneous immersion of the thermometers in a flask of deionized water or ethanol and then placing the flask containing both thermometers in the instrument being monitored until the deionized water or ethanol reaches the temperature of interest. 10.5 To point-check the accuracy of the Kessler maximum registration thermometers, place the thermometer to be checked and the ISO 17025 accredited verification thermometer (mercury in teflon-coated glass; section 7.2) side-by-side in one of the laboratory's autoclaves and run a sterilization cycle (e.g., gravity 15 minute cycle). 10.6 Any difference in temperature readings between the ISO 17025 accredited verification thermometer and the laboratory thermometer is recorded on the Point- Check Calibration of Laboratory Thermometers Record Form (see 16.0). 10.7 A label displaying the date of calibration and correction factor (even if it is zero), is placed around the top of the corresponding thermometer. 10.8 Digital thermometers and thermometer/hygrometers are indicated to be within tolerance. No correction factor is indicated on the calibration certificates. 11.0 DATA ANALYSIS/CALCULATIONS: 11.1 The Check Point for both the ISO 17025 accredited verification thermometer and the thermometer being calibrated is the reading on the ISO 17025 accredited verification thermometer during the point-check process. The temperature reading on the ISO 17025 verification thermometer must be within the range at which the thermometer to be calibrated will be used or is being used (see SOP QC-05, Monitoring Temperatures, for acceptable temperature ranges for equipment). 11.2 The Observed Temperature is the temperature reading of the thermometer during the check point process. 11.3 The correction factor for the ISO 17025 accredited verification thermometer is determined by the accredited company that performs the calibration verification for this thermometer. The True Temperature measured by the ISO 17025 accredited verification thermometer = the Observed Temperature of the ISO 17025 accredited verification thermometer plus its correction factor. 11.4 The correction factor for the laboratory thermometer that is being calibrated ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 7 of 10 against the ISO 17025 accredited verification thermometer is calculated by subtracting the Observed Temperature of the laboratory thermometer from the True temperature of the ISO 17025 accredited verification thermometer. 11.5 The True Temperature measured by the laboratory thermometer = the Observed Temperature plus the correction factor for that thermometer. 12.0 DATA MANAGEMENT/RECORDS MANAGEMENT: 12.1 Data will be recorded promptly, legibly and in indelible ink on the Point-Check Calibration of Laboratory Thermometers Record Form. Completed forms are archived in the Point-Check Calibration of Laboratory Thermometers Record Book. Annual Thermometer Calibration Reports for ISO 17025 accredited verification thermometers, including vendor-certified digital thermometers, Kessler maximum registration thermometers, and thermometer/hygrometers, are stored in the Thermometer and Hygrometer Calibration Certificates notebook. The books are kept in a secured file cabinet in the file room D217. Only authorized personnel have access to the secured files. Archived data are subject to OPP's official retention schedule contained in SOP ADM-03, Records and Archives. 12.2 An inventory of ISO 17025 accredited verification thermometers requiring vendor calibration will be maintained electronically (refer to 16.2). After each addition to or deletion from the inventory, a hard copy of the inventory will be filed in the Thermometer and Hygrometer Calibration Certificates notebook. 13.0 QUALITY CONTROL: 13.1 The OPP Microbiology laboratory conforms to 40 CFR Part 160, Good Laboratory Practices. Appropriate quality control measures are integrated into each SOP. 13.2 ISO 17025 accredited verification thermometers are certified once a year by an ISO 17025 accredited vendor. 13.3 Autoclave (section 7.2) and water bath thermometers (included in section 7.5) are point-checked once a year in the laboratory. All other thermometers in section 7.5 are point-checked on an as-needed basis, depending upon the functionality of the EMAS. Once performed, thermometers may be used for one year, at which point the point-check must be repeated. 13.4 For quality control purposes, the required information is documented on the ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 8 of 10 appropriate form(s) (see 16.0). 14.0 NONCONFORMANCE AND CORRECTIVE ACTION: 14.1 When routinely recording temperatures for the laboratory, laboratory equipment, media etc., the observed temperature reading of the thermometer read plus the correction factor for that specific thermometer must be recorded. 14.2 On occasion, thermometers must be discarded (e.g., broken columns, unreasonably large correction factor). Contact the facility Safety, Health, and Environmental Management Program Manager for proper disposal procedures. 15.0 REFERENCES: None 16.0 FORMS AND DATA SHEETS: 16.1 Point-Check Calibration of Laboratory Thermometers Record Form 16.2 Sample Inventory of Thermometers Requiring Vendor Calibration ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 9 of 10 16.1 Point-Check Calibration of Laboratory Thermometers Record OPP Microbiology Laboratory Dale Initials Thermometer Type Serial # Check- point'!' Observed Tcmp.ff Correction Factor * True Temp. ** ISO 17025 Accredited Verification Thermometer Comments Date Initials Thermometer Type Serial # Check- point f Observed Tcmp.ff Correction Factor * True Temp. ** ISO 17025 Accredited Verification Thermometer Comments Date Initials Thermometer Type Serial # Check- point t Observed Tcmp.ff Correction Factor * True Temp. ** ISO 17025 Accredited Verification Thermometer Comments f Reading on the ISO 17025 accredited verification thermometer during the point-check process. The temperature reading on the ISO 17025 accredited verification thermometer must be within the range at which the thermometer to be calibrated will be or is being used (See SOP QC-05, Monitoring Temperatures, for acceptable temperature ranges for equipment). Temperature reading of thermometer during the point-check process. * Correction factor for ISO 17025 accredited verification Thermometer determined by the Certification company. Correction factor for the thermometer being calibrated is calculated by subtracting its observed temperature from true temperature of ISO 17025 accredited verification Thermometer. ** True Temperature of ISO 17025 accredited verification Thermometer = Observed Temp.+ Correction factor: True temperature of Thermometer being Calibrated = Observed Temp. + Correction Factor for that thermometer. ------- SOP No. EQ-02-06 Date Revised 07-14-11 Page 10 of 10 16.2 Sample Inventory of Thermometers Requiring Vendor Calibration OPP Microbiology Laboratory Thermometer Type (Calibrated by) Manufacturer/Model # (if applicable) Serial Number Liquid in Glass (Innocal Solutions) ERTCO 1294 Kessler Maximum Registration Thermometer (autoclaves) (Innocal Solutions) ERTCO 7283 Digital Thermometers (Control Company) Control Company, model #4015 111320371 Control Company, model # 06-664-23 240106521 Control Company, model #4015 91313194 Thermometer/Hygrometers (Control Company) Control Company, model # 4184 102115627 Control Company, model # 11-661-12 111288367 Control Company, model # 61161-324 99372818 Control Company, model # 4184 102023201 ------- |