Measurement and Test Norm of Thermostatic Bath’s Metrological Characteristics
Some standard content:
National Metrology Technical Specification of the People's Republic of China JJF1030--2010
Technical Performance Test Specification for Thermostatic Baths
Measurement and Test Norm of Thermostatic Bath'sMetrological Characteristics2010-09-06 Issued
Implementation on 2011-03-06
General Administration of Quality Supervision, Inspection and Quarantine
JJF1030-2010
Technical Performance Test Specification for Thermostatic Baths
Measurement and Test Norm of ThermostaticBath'sMetrological CharacteristicsJJF1030-—2010
Replaces JJF1030--1998
This specification was approved by the General Administration of Quality Supervision, Inspection and Quarantine on September 6, 2010, and will be implemented on March 6, 2011.
Responsible unit: National Technical Committee on Temperature Metrology Main drafting unit: Beijing Institute of Metrology and Testing Science Participating drafting unit: China Institute of Metrology Guangdong Institute of Metrology
Shanghai Institute of Metrology and Testing Technology
Beijing Conster Instrument Technology Co., Ltd. This specification is interpreted by the National Technical Committee on Temperature Metrology Main drafters of this specification:
JJF1030-2010
Zhang Ke (Beijing Institute of Metrology and Testing Science) Zhang Zhe (China Institute of Metrology)
Participating drafters:
Yao Min (Beijing Institute of Metrology and Testing Science) Liang Xianyou (Guangdong Institute of Metrology) Wu Jianying (Shanghai Institute of Metrology and Testing Technology) Liu Baoqi (Beijing Conster Instrument Technology Co., Ltd.) Zhang Yinong (Beijing Institute of Metrology and Testing Institute of Science) 1
2 Terminology...
3 Overview·
4 Test conditions
4.1 Environmental conditions
4.2 Measuring standards and supporting equipment
5 Test items and test methods.
5.1 Test items·
5.2 Test methods·
JJF1030—2010
Appendix A Uncertainty evaluation of measurement results of temperature uniformity of constant temperature bath Appendix B Uncertainty evaluation of measurement results of temperature fluctuation of constant temperature bath (1)
(2)
(5)
1 Scope
JJF1030—2010
Technical performance test specification of constant temperature bath
This specification applies to the test of temperature stability and uniformity of liquid constant temperature baths used for verification or calibration. 2 Terminology
2.1 Thermostatic bath working space Thermostatic bath working space The area that can ensure the temperature stability and uniformity of the thermostatic bath. 2.2 Thermostatic bath temperature volatility refers to the range of temperature changes in the thermostatic working area within a certain time interval. 2.3 Thermostatic bath temperature uniformity refers to the difference between the highest temperature and the lowest temperature in the thermostatic bath working area. 2.4 The top horizontal plane of working space refers to the highest horizontal plane in the thermostatic bath working area. 2.5 The bottom horizontal plane of working space refers to the lowest horizontal plane in the thermostatic bath working area. 2.6 Fixed standards for platinum resistance thermometer The thermometer is fixed in the thermostatic bath working area and is used to measure the temperature change of the thermostatic bath. 2.7 Moving standards for platinum resistance thermometer The thermometer moves in the thermostatic bath working area and is used to measure the temperature change of the thermostatic bath. 3 Overview
Thermostatic bath uses liquid as heat transfer medium. Through the temperature control system and the action of stirring or jet device, it reaches the set temperature and keeps the temperature of its internal working area stable and uniform. It is mainly used as the constant temperature equipment required for the verification and calibration of various thermometers or other measuring instruments. Heat pipe bath can also be tested in accordance with this specification. The schematic diagram of the thermostatic bath working area is shown in Figure 1.
Working area
Upper horizontal plane
Working area
Lower horizontal plane
Figure 1 Schematic diagram of the thermostatic bath working area
4 Test conditions
JJF1030--2010
4:1 Environmental conditions
Environmental temperature: 15℃～35℃ or meet the requirements in the product manual; Environmental humidity: 35%RH~85%RH or meet the requirements in the product manual. Environmental conditions should also meet other use requirements of electrical measuring instruments and equipment. 4.2 Measuring standards and supporting equipment See Table 1 for measuring standards and supporting equipment. Measuring standards and supporting equipment Equipment name Platinum resistance thermometer Temperature measuring bridge Low thermal potential Conversion switch Technical requirements Accuracy 0.02 level: Identification equivalent to 1mK Stray potential <0.4μV Note: * When using two temperature fields with the same material, consider the thermometer itself Thermal image Test items Self and measurement Test method
Test items
Thermal resistance sheet
Use standard platinum resistance thermometer,
temperature measuring circuit or other measuring systems that meet
the following requirements can also be used:
The combined expanded uncertainty
induced by the standard instrument and the matching equipment shall comply with the requirements of the acid testing constant temperature bath
fluctuation and uniformity
measuring disk
stability and uniformity, among which the uniformity includes the temperature difference of the upper horizontal surface.
5.2 Test method
For the fluctuation
(i.e., the uncertainty value is not 1/3 of the absolute value of the uniformity)
The meter measures the temperature difference between the vertical
metal sheathed platinum resistance thermometer
and the maximum
temperature in the working area
5.2.1 Preparation before the test
Before the test, the power of the electric measuring equipment must be turned on for preheating. The preheating time must be at least 20 minutes or meet the corresponding requirements of the instruction manual of the electric measuring equipment.
Make the constant temperature bath in normal working state according to the requirements of the instruction manual, and ensure that the liquid level in the working area is at the specified position.
5.2.2 Fluctuation test
The fluctuation test of the constant temperature bath is generally carried out at the upper and lower limits of the actual working temperature range of the constant temperature bath. According to the needs of users, the fluctuation of other temperature points in the working temperature range of the constant temperature bath can also be sampled. Set the temperature of the thermostat bath to the lower limit temperature (or upper limit temperature), insert a thermometer into the 1/2 depth position in the working area, and wait for the thermostat bath to reach the set temperature for the first time and stabilize for at least 10 minutes or the stabilization time required by the thermostat bath manual before reading. When starting to read, the actual temperature of the thermostat bath (based on the standard instrument) should not deviate from the test point temperature by more than ±0.2℃. Read the indication at an even interval of at least 6 times per minute for 10 minutes or the time specified in the thermostat bath manual. Take the difference between the maximum and minimum values and convert it into a temperature value, which is the volatility of the thermostat bath within the corresponding time interval of the lower limit temperature (or upper limit overflow). 5.2.3 Uniformity Test
The temperature points for uniformity test are generally selected at the upper and lower limits of the actual working temperature range of the thermostat bath. The test location is generally selected at a typical location evenly distributed on the upper and lower horizontal planes of the working area. See positions A, B, C, D, E, F, G and H in Figure 1.
According to user needs, other temperature points within the working temperature range of the thermostat can also be sampled; other positions within the working area of the thermostat can also be sampled.
5.2.3.1 Test steps
Set the temperature of the thermostatic bath at the lower limit temperature (or limit temperature). Insert a thermometer as a fixed thermometer into the working area 1/2 depth and fix it on the reference plate. Position the other thermometer on the upper horizontal plane as shown in Figure 2. Wait until the thermostatic bath reaches the set temperature for the time required by the instruction manual of the thermostatic bath. Insert the thermometer as a mobile thermometer into the working area. After it stabilizes for at least 10 minutes, the reading can be read. When the reading is started, the actual temperature of the thermostatic bath (based on the standard instrument) should not deviate from the temperature of the test point by more than 0. Press the measurement sequence of fixed thermometer-mobile thermometer-mobile thermometer→fixed thermometer, fixed thermometer→mobile thermometer-mobile thermometer→fixed thermometer, and obtain the indicated values RA
RAI, RA, R&, R RA3, RM, R.
Mobile thermometer
ThermometerwwW.bzxz.Net
Figure 2 Schematic diagram of upper horizontal surface uniformity test
Upper water sheep surface
Working area
Lower horizontal surface
Calculate the average value of the fixed thermometer indication: R-(RA+R2+RRa+R&)/4Calculate the average value of the mobile thermometer indication: R.=(R+R+RAa+R)/4Then the temperature indication difference between point A and point (at this time is JJF1030--2010
RAORA-R
Keep the original position of the fixed overflow meter, and insert the mobile thermometer into the lower horizontal surface position E in the working area, as shown in Figure 3. Readings can be made only after the indications of the two thermometers have stabilized. Press Fixed thermometer→mobile thermometerMobile thermometer→fixed thermometer→fixed thermometer→mobile thermometerMobile thermometer-fixed thermometerThe measurement order is R, REL, Ra, R, R, R, Re, R. Fixed thermometer
Mobile thermometer
Working area
Upper horizontal plane
Working area
Lower horizontal plane
Figure 3 Schematic diagram of lower horizontal plane uniformity test
Calculate the average value of the fixed thermometer indication: Rg=（R+R+R+R）/4Calculate the average value of the mobile thermometer indication: Re=（R+Re2+Re3+R）/4Then the indication difference between point E and point O is
RE-O-RE-R
And so on According to the above method, the indication differences RBo, Rc-O, Rpo, RrO, RG-O, and RHO of points B, C, D, F, G, and H relative to point O in the working area can be obtained respectively. 5.2.3.2 Numerical calculation
Find the maximum and minimum values in RAO, RBO, Rco, and Rno. The difference between the maximum value and the minimum value is converted into temperature, which is the maximum temperature difference of the upper horizontal plane in the working area. Similarly, the maximum temperature difference of the lower horizontal plane in the working area can be obtained through R-0, Rr-O, RG-0, and Ro. Find the maximum and minimum values in RA-O, RBO, RcO, RD0, Re0, RF-0RG-O, and RHn. The difference between the maximum value and the minimum value is converted into temperature, which is the maximum temperature difference of the working area. 4
Appendix A
A.1 Measurement method
JJF1030—2010
Uncertainty assessment of the measurement results of the temperature uniformity of the constant temperature bath Select two second-class standard platinum resistance thermometers, equipped with a high-precision digital multimeter HY2003A, for measurement. One is fixed as a fixed thermometer at a point in the working area of the constant temperature bath, and the other is fixed as a mobile thermometer at points A and B in the working area. The temperature difference between point OA and point OB is obtained by the "reference position" method, and the temperature difference between point A and point B is obtained by the difference between the two. The test temperature is selected as 50℃. , A.2 Mathematical model
The temperature difference between points A and B in the working area of the constant temperature bath is △tA-B(RA-o-RBo)/ (dR/dt)ttWhere: tA-B The temperature difference between points A and B in the working area of the constant temperature bath, C: RA-the resistance difference between point OA and point O, n; RBoThe resistance difference between point B and point O, 2; (dR/dt)-the resistance change rate of the standard platinum resistor at the test temperature point t. When the resistance value is converted into a temperature value, formula (B.1) can be expressed as ATAB = (AtAO-△IBO)
A.3 Sources of uncertainty
(1) Uncertainty introduced by measurement repeatability (2) Uncertainty introduced by △tAo term
(3) Uncertainty introduced by Ao term
A.4 Calculation of standard uncertainty components
A.4.1 The standard uncertainty component u(B.1) introduced by measurement repeatability is at 50°C, according to The test method of this specification tests the temperature difference between points A and B 10 times and obtains s=0.001℃, then
ui0.001℃=1mK
A.4.2The standard uncertainty component u2 introduced by the u (AtA-o) item mainly includes the short-term stability of the difference between the two standard platinum resistance thermometers, the resolution of the electrical measuring instrument, the inconsistency of the temperature change in the two measuring holes, etc. (Since the ranges of the two platinum resistances are basically the same, the uncertainty introduced by the short-term stability of the electrical measuring instrument can be ignored), which belongs to Class B assessment. (1) The standard uncertainty u2.1 introduced by the short-term stability between two standard platinum resistance thermometers. The change between two standard platinum resistance thermometers in a short period of time (generally no more than 10 minutes) is estimated to be 1mK. If treated as uniform distribution, then u2.1=1//3=0.58 (mK)
(2) The standard uncertainty u2.2 introduced by the resolution of electrical measuring instruments. The resolution of HY2003A digital multimeter is 0.1mK (using Pt25Q2 platinum resistance is equivalent to 1mK). The half width of the reading interval is half of the resolution, that is, a=1/2=0.5 (mK). If treated as uniform distribution, then 5
JJF1030--2010
u2.20.5// 30.29 (mK)
(3) Standard uncertainty u2 introduced by inconsistent temperature changes in the two measuring holes. Two platinum resistance thermometers are inserted into two holes respectively. There is a possibility of inconsistent temperature changes in the two holes, which is estimated to be no more than 1mK. The half-width interval is taken as 0.5mK and treated as uniform distribution, then u2:a=0.5//30.29 (mK))
A.4.3 The standard uncertainty component u3 introduced by the u (△tB-o) item mainly includes the short-term stability between the two standard platinum resistance thermometers, the resolution of the electrical measuring instrument, the inconsistency of temperature changes in the two measuring holes, etc. (Since the measuring ranges of the two platinum resistances are basically the same, the uncertainty introduced by the short-term stability of the electrical measuring instrument can be ignored), which belongs to Class B assessment.
(1) Standard uncertainty introduced by short-term stability between two standard platinum resistance thermometers u3.1 The change between two standard platinum resistance thermometers in a short period of time (generally not more than 10 minutes) is estimated to be 1mK. If treated as uniform distribution, then us.m-1//3=0.58 (mK)
(2) Standard uncertainty introduced by resolution of electrical measuring instruments u3.2 The resolution of HY2003A digital multimeter is 0.1mK (equivalent to 1mK using Pt25α platinum resistor). The half-width of the reading interval is half of the resolution, that is, a=1/2=0.5 (mK). If treated as uniform distribution, then u3.20.5//3mm.0.29 (mK)
(3) Standard uncertainty introduced by inconsistency of temperature changes in two measuring holes us.3 Two platinum resistance thermometers are respectively inserted in two holes far apart. There is a possibility of inconsistency in the temperature changes in the two holes, which is estimated to be inconsistent. If it exceeds 1mK, take the half-width interval as 0.5mK and treat it as uniform distribution, then u3.30.5//3=0.29(mK)
A.5 Synthetic standard uncertainty
+++）+（++）
=12+(0.58+0.292+0.29）+（0.58+0.292+0.292)2.00
u.=1.41(mK)
A.6 Extended uncertainty If
takes 2, then
U=kXu,=2x1.4l3（mK)
Appendix B
B.1 Measurement method
JJF1030—2010
Uncertainty assessment of the measurement results of the temperature fluctuation of the constant temperature bath The constant temperature bath is stabilized at 50℃, a platinum resistance thermometer is inserted into the working area of the constant temperature bath at 1/2 depth, and a high-precision digital multimeter HY2003A is connected for measurement. Measure at least 6 times per minute for a total of 10 minutes. The difference between the highest value and the lowest value of the measurement result is converted into temperature, which is the range of the temperature change of the constant temperature bath. B.2 Sources of measurement uncertainty
(1) Measurement repeatability
(2) Short-term stability of electrical measuring instruments
(3) Resolution of electrical measuring instruments
(4) Short-term stability of standard platinum resistance thermometer, etc. B.3 Calculation of standard uncertainty components
B.3.1 Standard uncertainty component u introduced by measurement repeatability At 50℃, the temperature fluctuation at the same position was tested 10 times, and s=0.002℃ was obtained, so ui0.002℃=2mK
B.3.2 Standard uncertainty component u introduced by short-term stability of electrical measuring instruments The estimated value of the stability impact of HY2003A digital multimeter in a short period of time (generally not more than 10min) is 0.2mK (using Pt25Q platinum resistance is equivalent to 2mK), and according to the uniform distribution, uz=2//3=1.15(mK)
B.3.3 Resolution of electrical measuring instruments The introduced standard uncertainty component u3HY2003A digital multimeter has a resolution of 0.1mK (equivalent to 1mK using Pt25Q platinum resistance), and the half-width of the reading interval is half of the resolution, that is, α=1/2=0.5 (mK). If it is treated as a uniform distribution, then u0.5//3=0.29 (mK)
B.3.4 Short-term stability of standard platinum resistance thermometer The introduced standard uncertainty component uThe short-term stability (e.g. 10min) of the standard platinum resistance thermometer is estimated to be no more than 1mK. Take the half-width interval as 0.5mK. If it is treated as a uniform distribution, then
ux==0.5/30.29 (mK)||tt| |B.4 Combined standard uncertainty
=22+1.153+0.292+0.292
u.2.34(mK)
B.5 Expanded uncertainty
Take start=2, then
UkXu=2×2.345（mK）
National Metrology Technical Specification of the People's Republic of China
Technical Performance Test Specification of Constant Temperature Bath
JIF1030--2010
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