US Environmental Protection Agency Office of Pesticide Programs SOP for Maintenance and Calibration of Thermometers and Thermometer/Hygrometers Date Revised: 10-26-10 ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 1 of 9 EPA/OPP MICROBIOLOGY LABORATORY ESC, Ft. Meade, MD Standard Operating Procedure for Maintenance and Calibration of Thermometers and Thermometer/Hygrometers SOP Number: EQ-02-05 Date Revised: 10-26-10 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/ / Print Name: QA Officer Approved By: Date: / / Print Name: Branch Chief Effective Date: / / Controlled Copy No.: Withdrawn By: Date: / / ------- TABLE OF CONTENTS SOP No. EQ-02-05 Date Revised 10-26-10 Page 2 of 9 Contents Page Number 1.0 SCOPE AND APPLICATION 3 2.0 DEFINITIONS 3 3.0 HEALTH AND SAFETY 3 4.0 CAUTIONS 3 5.0 INTERFERENCES 4 6.0 PERSONNEL QUALIFICATIONS 4 7.0 SPECIAL APPARATUS AND MATERIALS 4 8.0 INSTRUMENT OR METHOD CALIBRATION 4 9.0 SAMPLE HANDLING AND STORAGE 4 10.0 PROCEDURE AM) ANALYSIS 4 11.0 DATA ANALYSIS/CALCULATIONS 5 12.0 DATA MANAGEMENT/RECORDS MANAGEMENT 6 13 .0 QUALITY CONTROL 6 14.0 NONCONFORMANCE AND CORRECTIVE ACTION 7 15.0 REFERENCES 7 16.0 FORMS AND DATA SHEETS 7 1.0 SCOPE AND APPLICATION: ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 3 of 9 1.1 This protocol describes the thermometers and thermometer/hygrometers in use in the laboratory, calibration requirements for NIST traceable thermometers and thermometers/hygrometers, and the procedure to point-check the accuracy of thermometers used to measure the temperature of water baths, incubators, refrigerators, and freezers. 1.2 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 a NIST traceable thermometer and employed to measure the temperature of incubators, refrigerators, and freezers. Vendor-calibrated thermometer/hygrometers are used to monitor the temperature/humidity of laboratories and sample storage areas. 2.0 DEFINITIONS: 2.1 NIST = National Institute of Standards and Technology. 2.2 Correction Factor = the difference in the vendor-certified NIST traceable 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. 3 .0 HEALTH AND SAFETY: 3.1 Teflon-coated mercury thermometers are permissible in 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 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 2600 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 ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 4 of 9 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: The NIST traceable thermometers are certified annually by an ISO 17025 certified vendor. To determine which thermometers are currently in use in the laboratory, refer to the Point Check Calibration of Laboratory Thermometers Record Book. 7.1 NIST traceable thermometers 7.2 NIST traceable Kessler maximum registration thermometers (ERTCO, mercury- containing/Teflon-coated) are used to verily autoclave temperatures. 7.3 NIST traceable digital thermometers for freezers 7.4 NIST traceable thermometers/hygrometers are used to measure temperature and humidity of laboratory rooms, incubators, and other spaces. 7.5 Thermometers 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 All thermometers are checked for accuracy using a NIST traceable thermometer. 9.0 SAMPLE HANDLING AND STORAGE: Not applicable 10.0 PROCEDURE AND ANALYSIS: 10.1 Annual Thermometer Calibration Reports for NIST traceable thermometers (sections 7.1 through 7.4) are stored in the Thermometer and Hygrometer Calibration Certificates notebook. 10.2 Once a year, all of the thermometers falling under section 7.5 of this SOP are checked at operating temperatures against one of the NIST traceable thermometers (section 7.1). ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 5 of 9 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 NIST traceable 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 NIST 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 simultaneous immersion of the NIST traceable 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 de-ionized water or ethanol and then placing the flask containing both thermometers in the instrument being monitored until the de-ionized water or ethanol reaches the temperature of interest. 10.5 Any difference in temperature readings between the NIST traceable thermometer and the laboratory thermometer is recorded on the Point-Check Calibration of Laboratory Thermometers Record Form (see 16.0). 10.6 A label displaying the date of calibration and correction factor (even if it is zero), is placed around the top of the corresponding thermometer. 10.7 Digital thermometers are calibrated against NIST traceable instrumentation and are indicated to be within tolerance. No correction factor is indicated (see certificates of NIST traceability). 11.0 DATA ANALYSIS/CALCULATIONS: 11.1 The Check Point for both the NIST thermometer and the thermometer being calibrated is the reading on the NIST thermometer during the point check process. The temperature reading on the NIST 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 NIST thermometer is determined by the certified company that performs the calibration verification for this thermometer. The True Temperature measured by the NIST traceable thermometer = the Observed Temperature of the NIST traceable thermometer plus its correction factor. ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 6 of 9 11.4 The correction factor for the laboratory thermometer that is being calibrated against the NIST traceable thermometer is calculated by subtracting the Observed Temperature of the laboratory thermometer from the True temperature of the NIST traceable 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 NIST traceable thermometers (sections 7.1, 7.2, 7.3, and 7.4) 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 NIST traceable thermometers requiring vendor calibration (sections 7.1 through 7.4) 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 Thermometers in sections 7.1 through 7.4 are calibrated once a year by a company certified to perform calibration verification of thermometers. 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. 13.3 For quality control purposes, the required information is documented on the appropriate form(s) (see 16.0). 14.0 NONCONFORMANCE AND CORRECTIVE ACTION: ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 7 of 9 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 Point Check Calibration of Laboratory Thermometers Record OPP Microbiology Laboratory Date Initials Thermometer Type Serial # Check- poinff Observed Temp.?? Correction Factor * True Temp. NIST Traceable Comments ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 8 of 9 ^ Date Initials Thermometer Type Serial # Check- point? Observed Temp.?? Correction Factor * True Temp. NIST Traceable Comments Date Initials Thermometer Type Serial # Check- point? Observed Temp.?? Correction Factor * True Temp. NIST Traceable Comments | Reading on the NIST thermometer during the point-check process. The temperature reading on the NIST 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). It Temperature reading of thermometer during the point-check process. * Correction factor for NIST Thermometer determined by the Certification company. Correction factor for the thermometer being calibrated is calculated by subtracting its observed temperature from true temperature of NIST Thermometer. ** True Temperature of NIST Thermometer = Observed Temp.+ Correction factor : True temperature of Thermometer being Calibrated = Observed Temp. + Correction Factor for that thermometer. Sample Inventory of Thermometers Requiring Vendor Calibration OPP Microbiology Laboratory Thermometer Type (Calibrated by) Manufacturer/Model # (if applicable) Serial Number NIST Traceable (Innocal Solutions) ERTCO 1294 3321 NIST Traceable Kessler Maximum Registration ERTCO 3400 4265 ------- SOP No. EQ-02-05 Date Revised 10-26-10 Page 9 of 9 Thermometers (autoclaves) 4315 (Innocal Solutions) 4330 7141 7223 7283 7286 7308 NIST Traceable Digital Fisher Scientific, 230317798 Thermometers model # 15-077-14 (Control Company) Fisher Scientific, model # 06-664-23 240106521 Control Company, 91313194 model #4015 NIST Traceable Control Company 91291344 Thermometer/Hygrometers Control Company 80595721 (Control Company) VWR 99372818 Control Company 101424304 ------- |