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1Presented by Jim & Deanne Emory REPLACING MERCURY CONTAINING PRODUCTS AND MERCURY THERMOMETERS IN ASTM STANDARDS Technical and Legal IssuesPresented by Jim & Deanne EmoryMiller & Weber, Inc.Ridgewood, NYJune 26, 2007
2Deanne Miller Emory James E. Emory, Jr. President & Owner of Miller & Weber, Inc.Precision Glass InstrumentsRidgewood, NYChairman, E20.05Liquid-in-Glass Thermometers & HydrometersChairman, ASTM E20Mercury Project Task GroupSecretary, E20.04on ThermocouplesMember-at Large, D02 Committee on PetroleumJames E. Emory, Jr.Judicial Referee andSenior Court AttorneyNew York StateOffice of Court AdministrationMember, E20Committee onTemperature MeasurementCONTACT US:(718)
3AbstractAt the request of several States, ASTM International has issued a directive to all technical committees to review their standards that reference mercury containing instruments or mercury methods and determine the technical and economic feasibility of replacing them or substituting with non-mercury instruments or methods. A number of States have banned the sale of mercury containing instruments, including ASTM mercury thermometers, making it difficult for users in those States to comply with ASTM standards. In most cases, the instruments in question are the mercury-in-glass thermometers specified in ASTM E1. These thermometers have long been the gold standard temperature measurement devices in many ASTM standards. In this presentation we will review the ASTM directive, including how to communicate the technical committees’ resolutions to ASTM; technical issues in replacing mercury containing devices with other devices, especially the thermometers found in ASTM E1; legal issues involved with this project, including which States have bans and how the bans differ from State to State. We will leave discussion time at the end of the presentation.
5NEWMOA The Northeast Waste Management Officials’ Association based in Boston, Massachusettsfound atNEWMOA’s mission is to develop and sustain an effective partnership of states to explore, develop, promote, and implement environmentally sound solutions for the reduction and management of materials and waste, and for the remediation of contaminated sites, in order to achieve a clean and healthy environment.The group fulfills this mission by providing a variety of support services that:Facilitate communication and cooperation among member states and between the states and the US EPA; andSupport the efficient sharing of state and federal program resources to help avoid duplication of effort and to facilitate development of regional approaches to solving critical environmental problems in the region.
6Member States Connecticut Maine Massachusetts New Hampshire New Jersey New YorkRhode IslandVermontNEWMOA was established by the Governors of the New England states as an official regional organization to coordinate interstate hazardous and solid waste, and pollution prevention activities and support state waste programs, and was formally recognized by the U.S EPA in 1986.
7IMERCIn 2001, NEWMOA established IMERC--- the Interstate Mercury Education & Reduction Clearinghouse.The State- Laws we will discuss first came out of this Clearinghouse.IMERC States include all of the NEWMOA states and California, Illinois, Minnesota, North Carolina and Washington.The IMERC website shows sample regulations and legislation to “help” the states get started on their bills.
8ASTM INITIATIVEHow did ASTM get involved with the states and organizations supporting the NEWMOA and IMERC models?
9ASTM InvolvementIn January 2006, state environmental agencies became aware of Federal and State rules and regulations that require the use of ASTM standards. Many of these standards require the use of mercury in glass (ASTM E1) thermometers.States began to lobby ASTM to remove requirement of mercury in their standards.A conference call in January 2006 with participants from state environmental groups, industry – including manufacturers of temperature measurement devices and users- including members of ASTM and other trade groups. There were also members of the NIST temperature measurement group and an occasional lawyer on the phone call.During the conversation it became apparent that ASTM played an important part in the industries affected by the bans.Rather than accept that some of these devices were necessary, the states began to lobby ASTM to remove requirements for mercury instruments and methods from their standards.
10ASTM SearchIn response to the requests, ASTM searched through their standards for references to ASTM E1, mercury, mercury-in-glass thermometers and liquid-in-glass thermometers.ASTM E1 is the most referenced standard within ASTM- it is referenced in over 900 standards.
11ASTM ResponseASTM Headquarters has requested each technical committee to review standards and determine whether the use of “mercury” or “mercury products” is appropriate; if it can be replaced or supplemented with non-mercury methods or products; if the reference should be removed without replacement of method or product.
12ASTM E20 Mercury Project Task Group Consists of seven members of ASTM Committee E20 to help provide technical guidance to the committees affect by this review.We have technical experts in liquid-in-glass thermometry, resistance thermometry, themocouples, radiation thermometry, thermistors and in calibration and construction.Guidance document developed for distribution to Subcommittee Chairmen and is available today.In order to help the technical committees, a mercury project task group was formed with ASTM Committee E20 on temperature measurement.
13ASTM Committee E20 on Temperature Measurement Overview of Committee and Committee Standards
14Technical Subcommittees E Radiation ThermometryE Resistance ThermometryE ThermocouplesE Liquid-in-Glass Thermometers and HydrometersE New Thermometers & TechniquesE FundamentalsE Medical Thermometry
15Hydrometers & Thermohydrometers ASTM Committee E20 Temperature Measurement ASTM Subcommittee E Liquid-in-Glass Thermometers and HydrometersHydrometers & ThermohydrometersASTM E100 “Standard Specification for ASTM HydrometersASTM E126 “Standard Test Method for Inspection, Calibration and Verification of HydrometersNEW “Standard Specification for ASTM Thermohydrometers using Non-Mercury Liquids”NEW “Standard Specification for Electronic Thermohydrometers (densitometers) using the Digital Buoyancy Method”NEW “Standard Test Method for Calibration and Verification of Electronic Thermohydrometers (Densitometers)”Liquid-in-GlassThermometersASTM E1 “Standard Specification for ASTM Liquid-in-Glass Thermometers”ASTM E77 “Standard Test Method for Inspection and Verification of Thermometers”ASTM E2251 “Standard Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids”) ASTM E1- most referenced and cross referenced standard in ASTM. It has over 130 different thermometers specified for use in ASTM test methods.ASTM E77- calibration method for liquid-in-glass thermometers(ASTM E Newest E20.05 standard for substitutes for a number of the ASTM thermometers shown in ASTM E1. This standard allows the user to substitute a glass thermometer, of high precision, for the mercury in glass thermometer currently used. We will discuss this standard in detail.ASTM E100- Specification for the hydrometers and thermohydrometers specified in ASTM test methods.(ASTM E126 test method for calibration of hydrometers.We are working on three new methods for density measurement to substitute for the mercury filled thermohydrometers.() The first is a specification of spirit filled thermohydrometers. The precision of these instruments and maximum scale error will not be as good as for the mercury filled instruments.The second and third are for standards for digital densitometers using the digital buoyancy method. One will be the manufacturing specification and the other the calibration method.We have also just started working on standards for general purpose liquid in glass thermometers and hydrometers no otherwise controlled by ASTM standards.
16ASTM Committee E20 Temperature Measurement Other Standards of Interest Resistance ThermometryE644- Standard Test Methods for Testing Industrial Resistance Thermometers.E1137- Standard Specification for Industrial Platinum Resistance ThermometersThermocouplesE220- Standard Test Method for Calibration of Thermocouples by Comparison TechniquesE230- Specification for Temperature- Electromotive Force (EMF) Tables for Standardized ThermocouplesFundamentalsE563- Standard Practice for Preparation and Use of an Ice-Point Bath as a Reference Temperature
17SUMMARY STATE BANS ON MERCURY-IN-GLASS THERMOMETERS as of June 15, 2007
18CALIFORNIA Effective July 1, 2006 A person shall not sell, offer to sell, or distribute for promotional purposes, any of the following new or re-furbished mercury-added products….Barometer… flow meter… hydrometer… hygrometer… psychrometer… manometer… pyrometer… thermometer.This does not apply to the sale of a mercury-added product if the use of the product is required under federal law or federal contract specification or if the only mercury-added component in the product is a button cell battery.California Codes Health and Safety Code
19CONNECTICUT Effective July 1, 2004 (add’l req. July 1, 2006) … no person shall offer for sale or distribute for promotional purposes any mercury-added product if the mercury content of the product exceeds 100 mg in the case of fabricated mercury-added products or 50 ppm in the case of formulated mercury added productsManufacturer may apply for an exemption.Connecticut Chapter 446m Mercury Reduction and Education Sec
20INDIANA Effective July 1, 2003 A person may sell or provide a mercury commodity to another person in this state (other than for collecting for recycling) only if: (1) the person selling or providing the mercury commodity provides an MSDS… (2) person selling or providing the mercury commodity requires that the purchaser or recipient will (a) use the mercury only for medical purposes, in dental amalgam, dispose-caps, for training, for research or for manufacturing purposes (b) understands that mercury is toxic, (c) will store and use properly.. (d) will not intentionally place… in solid waste for disposal or in a wastewater disposal system.Indiana IC
21MAINE Effective July 1, 2006A person shall not sell or offer to sell or distribute the following mercury-added products:Barometer… flow meter… hydrometer… hygrometer or psychrometer… manometer… pyrometer… thermometer…This section does not apply to the sale of the above products if the use of the product is a federal requirement or if the only mercury-added component in the product is a button cell battery. Manufacturer may apply for an exemption.Maine Title 38, Chapter 16-B, Section 1661-C-6
22MASSACHUSETTS Effective May 1, 2007 Manufacturers of products to which mercury has been intentionally added and that are sold in the state must establish a system of collecting them at the end of their useful lives, and for recycling their mercury contents. The plan must be approved and certified by the department.Unless the mercury-added product is required under federal law.Massachusetts Chapter 190 of the Acts of 2006, Section 6J
23MICHIGAN Effective January 1, 2003 (Ban includes) all mercury thermometers sold or offered for promotion……except those (1) required by state or federal statute, regulation, or administrative rule, (2) used for pharmaceutical research purposes.Enforcement shall be done by dept of environmental quality. A person who violates this part is guilty of a misdemeanor punishable by imprisonment of not more than 60 days or a fine of not more than $1,000.00, or both, plus the costs of prosecution.Michigan Act 451 of 1994,Sections &
24MINNESOTA Effective January 1, 2002 Includes all mercury thermometers manufactured after June 1, 2002,Except those (1) used for food research and development or processing, (2) are a component of an animal agriculture climate control system or industrial measurement system, until a system is replaced or a non-mercury component is available, (3) used for calibration of other thermometers, apparatus or equipment unless a nonmercury calibration standard is approved by NIST and (4) electronic thermometers with button cell batteries.Minnesota Chapter 47- H.F. No 274
25NEBRASKA Effective May 20, 2003 No liquid mercury thermometer containing elemental mercury shall be sold, given away, or otherwise distributed in this state.No exceptions in statute.Nebraska Chapter 28, Section & (Laws of 2003, LB 17 Section 3 & 4)
26NEW YORK Effective January 1, 2007 (Bans) all mercury-added manometers and hydrometers,except those used to replace a product that is a component in a larger product in use prior to January 1, 2007, or the resale of a manometer or hydrometer manufactured before December 31, 2006.New York Title 21, Section ,6
27NEW YORK Effective January 1, 2008 Cannot sell, offer for sale, or distribute mercury-added thermometers if a non-mercury alternative is available. Commission will review this by February 2008 and rule if non-mercury alternatives are available.Excludes mercury-added thermometers that are a component of a larger product in use prior to January 1, 2008 or resale manufactured before January 1, 2008; excludes if the use is a federal requirement.New York Title 21, Section ,8
28RHODE ISLAND Effective January 1, 2006- revise 1/1/07 & 1/1/08 No mercury added product shall be offered for final sale or use or distributed for promotional purposes in the state if the mercury content of product exceeds 1 gram for fabricated products and 250 ppm for formulated products.Excludes are lighting for entertainment industry and fluorescent lamps and HID lamps. Manufacturers may apply for exemption.Rhode Island Title 23, Health & Safety,Mercury Reduction & Eductation Act.Chapter
29VERMONT Effective January 1, 2007 Restricts the sale of thermometers that contain elemental mercuryExcludes if it is for a Federal requirement.Also … barometers… flow meters… hygrometers & psychrometers… manometers… hydrometers.Excludes Hygrometers, psychrometers & manometers if replacing into larger device in place before 1/1/07. Exemptions may be granted.Vermont Chapter 164, Section 7105
30WASHINGTON Effective January 1, 2006 (Ban) includes all mercury thermometers…except those (1)electronic thermometers with a button cell battery containing mercury (2) used for food research and development or processing including meat, dairy products, and pet food processing, (3) are a component of an animal agriculture climate control system or industrial measurement system, until a system is replaced or a non-mercury component is available, (3) used for calibration of other thermometers, apparatus or equipment unless a nonmercury calibration standard is approved by NIST and (4) electronic thermometers with button cell batteries.Washington Chapter 70.95M.050
31So, how do we substitute for this? Hundreds of ASTM test methods specify and rely on mercury-in-glass thermometers as defined by ASTM Standard E1.There are different ways to accomplish the substitution of a mercury in glass thermometer.
32Automated Viscometer Automated Cloud & Pour If money is not an object- fully automated systems are available that use micro-processor controlled temperature measurement devices.These devices have software that hold algorithms necessary to give temperature results that mimic the glass thermometer results.Unfortunately, automated methods equivalent to the manual methods for many tests do not yet exist.Automated Cloud & Pour
34Thermometer Types Standard Platinum Resistance Thermometers (SPRTs) (very accurate, but susceptible to shock)13.8 K to 962 °C (Calibration uncertainty less than °C *)Industrial Platinum Resistance Thermometers (IPRTs)–196 °C to 850 °C (Calibration uncertainty less than 0.01 °C *)Thermistors–10 °C to 100 °C (Calibration uncertainty less than °C *)Liquid-in-Glass Thermometers–150 °C to 400 °C (Calibration uncertainty between 0.02 and 0.5 °C *)Thermocouples–196 ° C to 2100 °C (Calibration uncertainty between 0.3 and 1 °C *)* U (k=2)Information courtesy of NISTStandard platinum resistance thermometers- temperature standard at NIST. The SPRT itself (without readout device) will cost approximately $ Calibration will cost between $ dollars depending where and how it is calibrated.An IPRT will cost betwen $100 and $1000 and have a calibration cost of approximately $A thermistor will have a cost between $ 50 & 1000 and have a calibration cost of between $500 and 1000.Noble Metal thermocouples (which give the lower uncertainties will cost approx. $ and a base metal thermocouple between $5 and 50. Both will have a calibration cost of between $ Thermocouples are not good candidates for re-calibration.Liquid in glass, mercury filled thermometers have a nominal cost of $ and a calibration cost of between $
35Digital ThermometersA digital thermometer is an electronic “box” that converts either resistance or emf of a thermometer to temperature.Platinum Resistance Thermometers, thermistors and thermocouples in disguise.Many of the ASTM test methods found in ASTM are being re-written to allow substitute temperature measurement devices.Most are being written with simple statements that “other” devices are allowed as long as they will give at least as precise results as the mercury-in-glass ASTM thermometer.There are a number of pitfalls to that statement.First, a digital thermometer may be any of the sensors we just discussed. They are not interchangeable when it comes to performance characteristics.Pictures courtesy of Fluke/Hart Scientific, ASL and WL Walker Co.
36Thermometer Types: Calibration Ranges and Uncertainties Chart used with permission of NIST Thermometry Group
37Determine Differences in Scale Error and Uncertainties PRT’s and Thermistors COMPONENTMETHOD OF EVALUATIONCalibration uncertainty or toleranceManufacturer or calibration laboratoryAlternative sensor driftManufacturer’s specifications, or customer historyHysteresis of alternative sensor (PRTs only)ASTM Method E644, implemented by manufacturer or customerReadout uncertaintyManufacturer or independent evaluationReadout driftSome components of uncertainty that need to be evaluated are listed here.The calibration uncertainty or toleranceThe sensor driftIPRT’s exhibit hysteresis on thermal cycling, which means that the industrial PRT may have different but reproducible resistance versus Temperature relationships depending upon the thermal history of the thermometer and on whether a given temperature is being approached from lower or higher temperatures.Uncertainty and drift associated with the readout device.Used with permission of the NIST Thermometry Group
38Determine Differences in Scale Error and Uncertainties Thermocouple Sensors COMPONENTMETHOD OF EVALUATIONCalibration uncertainty or toleranceManufacturer or calibration laboratoryThermocouple driftResults from literature or in situ comparisons (see ASTM MNL 12)Reference junction uncertaintyManufacturer or independent evaluationReadout uncertaintyReadout driftThe chart for thermocouples is similar.Again, we need to look at calibration uncertainty or tolerance.The thermocouple drift and reference junction uncertainty.And any readout uncertainty and drift.Each of these components, expressed in units of temperature, as standard uncertainty needed to be added in quadrature to obtain the root-sum-of –squares total uncertainty.The sum of the components, at a coverage factor of 2 or 3, depending on the ASTM method should not exceed the maximum scale error of the E1 thermometer.Beyond the uncertainty study, thermocouples may not be the best choice of substitute instrument.If using a thermocouple above 100°C sensor drift must be carefully evaluated. The drift of base metal thermocouples will often exceed the maximum scale error of ASTM E1 thermometers. As an example, common base-metal thermocouples (types E, J, K, N and T), when exposed to temperatures of 200°C for several tens of hours, will experience drifts up to 0.5°C. As important, if the immersion of such a thermocouple is altered from the initial position, apparent sensor drift of up to 1.5°C may be observed.Used with permission of the NIST Thermometry Group
39Additional Constraints Sensor should be hermetically sealed in stainless steel sheath of outer diameter no larger than the bulb diameter of the E1 thermometer.When substituting for a partial immersion thermometer, immerse at least as deep as you would the glass thermometer. A bias may be introduced due to temperature gradients in the ASTM apparatus if the immersion is very different from the glass thermometer.When substituting for a total immersion thermometer, the center of the alternative sensor should be placed at a depth equal to the center of the liquid-in-glass thermometer. Again, bias may be introduced since PRT can be fixed in place and there may be temperature gradients.PRTs should be fabricated to ASTM E1137.Thermistors should be fabricated to ASTM E879.Thermocouples should be fabricated either of soft-insulated wire mounted in stainless-steel sheaths similar to the mountings described in E879 or E1137, or of mineralinsulated construction in conformance with E608.NIST makes additional recommendations when choosing an electronic substitute thermometer.(CLICK) The sensor should be hermetically sealed in a stainless steel sheath of outer diameter no larger than the bulb diameter of the E1 thermometer. In many cases the bulb spec is simply no greater than stem. In this case you must know the maximum od of the stem and make sure your sheath is smaller than that OD.(CLICK) When substituting for a partial immersion thermometer, the top of the alternative sensor should be immersed at least as deep as the thermometer bulb would be at the stated immersion. If a greater immersion is necessary to be sure of sufficient thermal equilibrium between the test fluid and the sensor, it may be necessary to evaluate the thermal non-uniformity of the test fluid for a particular test method. ASTM E644 describes a method for the measurement of minimum immersion depth of a PRT. This same method may be used for other types of thermometers.(CLICK) When substituting for a total immersion thermometer, the center of the alternative sensor should be placed at a dept equal to the center of the liquid in glass thermometer bulb, as it would be indicating temperature at the midpoint of the high and low temperatures encountered for a particular test method. As with the partial immersion thermometers, additional testing may be necessary if there are significant thermal non-uniformities of the test fluid.(CLICK) PRTs should be fabricated in conformance with ASTM Specification E1137(CLICK) Thermisters should be fabricated in conformance with ASTM Specification E879. Only metal sheathed thermistor probes should be considered acceptable.(CLICK) Thermocouples should be fabricated either of soft-insulated wire mounted in stainless-steel sheaths similar to the mounting described in ASTM E980 or E1137, or of a mineral insulated construction in conformance with ASTM Specification E608. The length of the sheath sould be long enough that any connectors or transition junctions will be well removed from the test fluid and located in a region of nominally ambient temperature.
40General Issues with Replacing Mercury-in-Glass Thermometers in ASTM Standards
41ASTM Total Immersion Liquid-in-Glass Thermometers Total immersion thermometers, when properly used have immersion depths that vary with temperature.Some ASTM total immersion thermometers (such as ASTM Calorimetry thermometers) are not manufactured to measure absolute temperature.ASTM Kinematic Viscosity thermometers have ice points that do not read absolute temperature.Many ASTM total immersion thermometers (such as distillation and saybolt viscosity thermometers) are used as partial immersion thermometers.(CLICK) Not every ASTM total immersion thermometer found in ASTM E1 or ASTM E2251 is manufactured to measure absolute temperature.(CLICK) A number of instruments, particularly the Calorimetric thermometers and the ice points on kinematic viscosity thermometers are calibrated with the bulbs of the thermometer completely expanded.In other words, the thermometer is first brought to its highest temperature and then calibrated. This is difficult to mimic in an electronic alternative device.However, we have been able to accomplish this with our E2251 alternative, which we will discuss in a few minutes.(CLICK) Many ASTM total immersion thermometers are used in methods as partial immersion thermometers. Good examples are saybolt viscosity thermometers and distillation thermometers.If we consider ASTM Methods on Distillation. The instruction says to use an ASTM 7C or 8C, immersed about 3 inches and the instruction specifically says NOT to correct for emergent stem temperatures.If we were to take an ASTM 8C and put next to it a good industrial PRT, we could expect to get differences in readings like this (CLICK)
42ASTM Distillation Manual Methods ASTM 8C vs Electronic Thermometer ReadingDifference in Readings50.0 °C49.9 °C-0.1 °C100.0 °C99.1 °C-0.9 °C150.0 °C147.5 °C-2.5 °C200.0 °C195.2 °C-4.8 °C250.0 °C242.0 °C-8.0 °C300.0 °C288.0 °C-12.0 °C350.0 °C333.3 °C-16.7 °C400.0 °C377.8 °C-22.2 °CAs I said earlier, automatic instruments have algorithms that correct for this error. However, if you use an electronic substitute, with a manual instrument, you will have to correct for these differences yourself.Help in doing these important corrections are found in an appendix of D86 and may also be added to other distillation methods.Round robins may be necessary to create formulae for adjusting for substituted instruments.GOLD STANDARD
43ASTM Partial Immersion Mercury-in-Glass Thermometers Many ASTM partial immersion mercury-in-glass thermometers have “artificially” high or low emergent stem temperatures.Study of differences in readings of mercury-in-glass thermometer and substitute thermometer (whether liquid-in-glass or electronic must be made before relying on the substitute thermometer.Special care must be taken when substituting in timed tests (ie flashpoint). Rate of rise and lag time must be accounted for.There are other sources of system error that must be considered before substituting an electronic thermometer into your manual testing unit.(CLICK) A number of ASTM E1 partial immersion thermometers have assigned emergent stem temperature values that may be arbitrary. Originally, many of the emergent stem temperatures were calculated to mimic conditions over the equipment they are used in. Over the years, the equipment has changed, but the thermometers have not.In some cases, the emergent stem temperatures are completely arbitrary as in the ASTM 6C and ASTM 133C.It was more important to the designers of these instruments that the best reproducibility be obtained. The absolute temperature was less important than everyone in the industry obtaining the same temperature.(CLICK) Tests with split samples, etc. should be done with the substitute thermometer and ASTM E1 thermometer to be sure there is no bias being introduced because of the emergent stem temperature.(CLICK) For timed tests, such as flash point studies, differences in rate of rise and lag time may be important. Studies must be done to see if there is an error or biased introduced by the alternate sensor.
44Typical Alternative Liquids typically available in thermometers Properties of Typical Alternative Liquids as Compared to MercuryLess hazardous than mercuryReaction time descending up to fifteen minutes.Repeatability less precise than mercuryToluene (ASTM 6C & ASTM 114C)KeroseneMineral SpiritsSiliconesCitrus OilsIsoAmyl BenzoateLet’s leave electronic alternatives and turn our attention to other types of liquid-in-glass thermometers.Traditionally, liquid-in-glass thermometers were made of mercury or spirit.Spirit being the generic name for a range of liquids from alcohols to mineral spirits to citrus oils. The slide identifies some of the commonly used non-mercury liquids used today.ASTM E-1 specifies two thermometers, ASTM 6C&F and ASTM 114C to be filled with toluene for low temperature work.Unfortunately, all of these liquids have the same problems.Although they are less hazardous than mercury, their reaction time descending can be as much as 15 minutes and their repeatability does not make them good choices for use in ASTM test methods that require mercury thermometers.All of the traditional liquids, whether considered plain spirits, or the environmentally safe non-mercury liquids, they will all “stick” to the walls of the thermometer.
45Typical non-mercury thermometers do not have tolerance, repeatability or response time adequate for use in ASTM standards.WHY?
46Behaviors of Traditional Liquids in Glass Capillaries The column on the left shows a typical mercury filled capillary.The column on the right shows a spirit or traditional non-mercury column.Spirit filled thermometers or traditional non-mercury thermometers are usually not appropriate as substitutes the mercury in glass ASTM thermometers.The uncertainties of any method will increase dramatically because of the change in precision of the thermometer.
47Desirable Behaviors of Mercury as a Thermometric Liquid Expands UniformlyWide useable range (-39 to 500 °C)Reaction time three minutesRepeatable measurement capabilityLet us look at the desireable behaviors of mercury as a thermometric liquid.It expands uniformly.It has a wide useable range.It will react ascending or descending through the column within 3 minutes.It has a repeatable measurement capability.
48Accepted by ASTM Committee E20 in November 2002. ASTM E2251 “Standard Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids”Written by the NIST Thermometry group and members of ASTM E20.05 based on the research presented at the 8th International Temperature Symposium in October 2002.Accepted by ASTM Committee E20 in November 2002.Published by ASTM in February 2003.Those of us involved in writing and editing ASTM E2251 are very proud of what we accomplished with this new standard.Like ASTM E1, it specifies ranges and dimension for thermometers designated ASTM.Unlike ASTM E1 which specifies that the liquids must be mercury, mercury-thallium or toluene, ASTM E2251 is a performance standard.The annex of ASTM E2251 specifies a group of performance characteristics for liquids used in this standard.We at Miller & Weber are very proud that the members of the task group writing this standard used our research, in part, to write ASTM E2251.Like most ASTM standards, ASTM E2251 went through several ballots and revisions, but in February 2003 was published in volume of the ASTM International Standards.Since its original publication, new thermometers have been added to the standard as the technical committees design and approve of alternative instruments using this technology.
49“Preliminary Results of a New Type of Non-Hazardous Liquid-Filled Precision Glass Thermometer” Research presented at the 8th International Temperature Symposium in Chicago, Illinois October 2002.Research published by the AIP in the Conference Proceedings. CP684, Temperature: Its Measurement and Control in Science and Industry, Volume 7. Edited by Dean C. Ripple.In 2002 we were invited by NIST to participate in the 8th International Temperature Symposium held in Chicago Illinois.We presented our research to the metrology world and were received enthusiastically.Our research was published by the American Institute of Physics in their conference proceedings “Temperature: It’s Measurement and Control in Science and Industry, Volume 7.
50PROPERTIES REQUIRED OF ASTM E2251 THERMOMETERS Liquid column will ascend or descend with change of temperature so that top of liquid column reaches final position within 3 minutes of attaining temperature to be measured.Liquid column will descend through a contraction chamber or ice point chamber and will reach final position within 3 minutes of attaining temperature to be measured.Liquid is biodegradableLiquid is non-toxic in thermometer quantities (per 49 CFR )Liquid is non-hazardous (per EPA Regulations)Thermometer will give repeatable results similar to those expected of a mercury thermometerThermometer will give reproducible results similar to those expected of a mercury thermometerSome of the important performance characteristics found in ASTM E2251 for thermometers meeting this specification are:(CLICK) The liquid column will ascend or descend with change of temperature so that the top of the liquid column reaches final position within 3 minutes of attaining the temperature to be measured.(CLICK) The liquid column will descend through a contraction chamber or ice point chamber and will reach final position within 3 minutes of attaining the temperature to be measured. This is particularly important to quantify, because up to the time the original “new” liquids were developed, no liquid other than mercury or mercury-thallium alloy was able to contract through a chamber to make thermometers with auxiliary ice points.(CLICK) the liquid is biodegradable(CLICK) non-toxic in thermometer quantities as defined by 49CFR(CLICK) non-hazardous per EPA regulations(CLICK) With all of the above met, the thermometer will give repeatable and(CLICK) reproducible results similar to those expected of a mercury thermometer, without the hazards.
51Behaviors of Traditional Liquids in Glass Capillaries If we go back to this slide you will see that spirit filled thermometers wet the capillary giving the undesireable effect of being non-repeatable and difficult to descend the liquid through the capillary.
52Current available E2251 Thermometers Thermometers currently being manufactured to ASTM E2251 show no meniscus under 5X magnification.Future generations now in R&D may show cohesive forces greater than adhesive forces as with mercury.
53Thermometers currently available and approved in ASTM E2251 ASTM S12C &F Density Wide RangeASTM S56C & F Bomb CalorimetryASTM S59C & F TankASTM S62C & F thruASTM S67C & F PrecisionASTM S91C DistillationASTM S116C Bomb CalorimetryASTM S117C Bomb CalorimetryASTM S120C Kinematic ViscosityASTM E20 has approved the following thermometers in ASTM E2251.No thermometer is added to the standard without a request from the technical subcommittee or committee that needs the instrument.ASTM E20.05 has a standing task group to address requests for thermometers to be added to ASTM E2251.
54So, how do we substitute for this? On to density by hydrometer method
55Subcommittee E20.05 is currently working on a new standard for thermohydrometers with non-mercury liquids.The draft standard, as currently written has the maximum permissible error of the thermohydrometer thermometers at approximately double the maximum permissible error of the mercury filled thermometers in the ASTM E100ASTM subcommittee E20.05 is currently working on a standard for spirit filled thermohydrometers.
56Glass Hydrometer Method If you are using a hydrometer method, the best alternative we have today is a plain form hydrometer with anASTM E2251ASTM S12C or ASTM S12F density thermometer in the cylinder to measure the temperature.If you are using a glass hydrometer method, the best alternative available, while keeping a glass hydrometer is a combination of plain form ASTM thermometer and a new ASTM Standard E2251 density thermometer, ASTM S12C or ASTM S12F.These density thermometers are the same as the mercury filled ASTM 12C and ASTM 12F, but filled with the E2251 liquid.They have the same maximum scale error allowances and the same uncertainties as the mercury filled thermometer.
57Digital Densitometers using the digital buoyancy method Newly available in the United States, these instruments can be used as direct replacements for glass hydrometers, glass thermohydrometers and they can do direct reading of density directly in the storage unit or tank car.They are durable, simple to use, and unlike U-tube densitometers, easy to clean.Designed and manufactured by Lemis- Baltic in Riga, Latvia, and newly available in the United States, these instruments can be used as direct replacements for glass hydrometers, glass thermohydrometers and they can do direct reading of density directly in a storage unit or tank car.They area available in ranges from 500 to 2000 kilograms per cubic meter and can convert to relative density, specific gravity and API gravity direct on the readout.They are durable, simple to use, and unlike U-tube densitometers, easy to clean.
58(CLICK) The instruments are available in high precision models for laboratory use. They will give measurements with accuracies like those attained with pycnometry and other high accuracy methods.(CLICK) The new Den Di and Den Di 2 instruments will give similar results to a hydrometer method. However, they use only 50 milliliters of sample and can be used with opaque samples.(CLICK) The portable immersible units can be used for direct measurments in tanks and storage cars.(CLICK) And extremely exciting is a unit that will measure density of liquid petroleum gases.
59What to do next?Decide whether you mercury-in-glass thermometer is a “gold standard”. If so, give rationale for leaving the method or instrument as a requirement to the standard.If you are going to allow substitutes, decide which types will be adequate for use in your standard.If necessary, do studies to identify whether your precision and bias statements will be affected.If necessary, have new thermometers that meet your subcommittee needs added to ASTM E2251.
60Finish work for ASTM Headquarters Ballot changes to standard- including the addition of a mercury caveat, if appropriate.Subcommittee respond back to ASTM on action to be taken in each standard identified in “the search”. This response can go to your staff manager.