CN102866180A - High-precision intelligent acidity meter and measuring method thereof - Google Patents

High-precision intelligent acidity meter and measuring method thereof Download PDF

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CN102866180A
CN102866180A CN2012103494080A CN201210349408A CN102866180A CN 102866180 A CN102866180 A CN 102866180A CN 2012103494080 A CN2012103494080 A CN 2012103494080A CN 201210349408 A CN201210349408 A CN 201210349408A CN 102866180 A CN102866180 A CN 102866180A
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analog switch
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严锡君
余敏
严妍
孟祥薇
孙桐
王玲玲
卜旸
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Hohai University HHU
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Abstract

本发明公开一种高精度智能酸度计及其测量方法,其A/D转换电路包括温度传感器、PH传感器、第一运算放大器、第二运算放大器、多路模拟开关和A/D转换器,温度传感器、PH传感器的输出分别经第一、第二运算放大器连接至多路模拟开关其中一个通道的多个输入端,多路模拟开关连接在第二运算放大器的反馈电路中,其另一通道的两个输出端分别连接有不同阻值的电阻。本发明测量方法在一点、两点校正时采用自动识别标准液的标定方法,同时采用温度补偿的方法校准标准液和被测液的PH值。本发明能够自动识别所标定的标准溶液PH值,能够根据环境温度校准标准液的PH值,减少了人工操作,大大提高了PH值的测量精度。

The invention discloses a high-precision intelligent acidity meter and its measurement method. Its A/D conversion circuit includes a temperature sensor, a PH sensor, a first operational amplifier, a second operational amplifier, a multi-channel analog switch and an A/D converter. The outputs of the sensor and the pH sensor are respectively connected to multiple input terminals of one channel of the multi-channel analog switch through the first and second operational amplifiers, and the multi-channel analog switch is connected to the feedback circuit of the second operational amplifier, and the two channels of the other channel Resistors with different resistances are respectively connected to the output terminals. The measuring method of the present invention adopts the calibration method of automatically identifying the standard liquid during one-point and two-point calibration, and simultaneously adopts the method of temperature compensation to calibrate the pH values of the standard liquid and the measured liquid. The invention can automatically identify the pH value of the calibrated standard solution, can calibrate the pH value of the standard solution according to the ambient temperature, reduces manual operations, and greatly improves the measurement accuracy of the pH value.

Description

高精度智能酸度计及其测量方法High precision intelligent acidity meter and its measuring method

技术领域 technical field

本发明公开了一种高精度智能酸度(PH)计及其测量方法,属于电子测控领域。The invention discloses a high-precision intelligent acidity (PH) meter and a measuring method thereof, belonging to the field of electronic measurement and control.

背景技术 Background technique

随着科学研究的发展和生产技术的进步,水分的定量分析已被列为各类物质理化分析的基本项目之一,作为各类物质的一项重要的质量指标,其PH值更是测定的重要数据。另外,对生产过程中或者涉及环境保护中液体、固体混合物PH值的测量和控制要求也日趋增多,所以作为分析仪表酸度计的使用也越来越普及了。酸度计简称PH计,由电极和测量电路两部分组成。使用中若能够合理维护电极、按要求配制标准缓冲液和正确操作电计,可大大减小PH示值误差,从而提高化学实验、医学检验数据的可靠性。With the development of scientific research and the progress of production technology, the quantitative analysis of moisture has been listed as one of the basic items of physical and chemical analysis of various substances. As an important quality index of various substances, its pH value is the most important important data. In addition, the requirements for the measurement and control of the pH value of liquid and solid mixtures in the production process or in environmental protection are also increasing, so the use of acidity meters as analytical instruments is becoming more and more popular. The acidity meter is referred to as a PH meter, which consists of two parts: an electrode and a measuring circuit. If the electrodes can be maintained reasonably, the standard buffer solution can be prepared according to the requirements, and the electrometer can be operated correctly during use, the error of pH indication can be greatly reduced, thereby improving the reliability of chemical experiment and medical inspection data.

现有的PH计,大多采用手工方法进行校验,温度补偿也是采用手动调节旋钮的方式进行,这种方法存在操作繁琐、受环境影响较大和精度过低的缺陷。同时,生产过程用PH计的维护工作量很大,如PH可能经常发生零点漂移、量程变化的问题,而人工校验PH计的工作量较大,且影响PH计的正常测量工作。为了克服以上缺陷,用自动校验取代人工校验,并且增加温度自动校准功能,是智能化PH计的发展趋势。Most of the existing pH meters are calibrated manually, and the temperature compensation is also carried out by manually adjusting the knob. This method has the defects of cumbersome operation, great influence of the environment and low accuracy. At the same time, the maintenance workload of the pH meter used in the production process is very heavy. For example, the pH may often have zero drift and range changes. The manual calibration of the pH meter requires a large workload and affects the normal measurement work of the pH meter. In order to overcome the above shortcomings, it is the development trend of intelligent pH meters to replace manual calibration with automatic calibration and increase the function of automatic temperature calibration.

PH计的自动校验装置近年来发展很快,它的发展是建立在PH计自动清洗装置、传感器在线自诊断功能的基础上的,因为要进行自动校验,前提是电极的清洗和标准液的准确。而传感器可以为PH计的自动校验提供基础数据。The automatic calibration device of the pH meter has developed rapidly in recent years. Its development is based on the automatic cleaning device of the pH meter and the online self-diagnosis function of the sensor. accurate. The sensor can provide basic data for the automatic calibration of the pH meter.

发明内容 Contents of the invention

技术问题:现有的PH计,大多采用手工方法进行校验,温度补偿也是采用手动调节旋钮的方式进行,这种方法存在操作繁琐、受环境影响较大和精度过低的缺陷。同时,生产过程用PH计的维护工作量很大,如PH可能经常发生零点漂移、量程变化的问题,而人工校验PH计的工作量较大,且影响PH计的正常测量工作。Technical problem: most of the existing pH meters are calibrated manually, and the temperature compensation is also carried out by manually adjusting the knob. This method has the defects of cumbersome operation, great influence of the environment and low precision. At the same time, the maintenance workload of the pH meter used in the production process is very heavy. For example, the pH may often have zero drift and range changes. The manual calibration of the pH meter requires a large workload and affects the normal measurement work of the pH meter.

一般地,标准溶液的浓度都是25°C环境温度下测得的PH值,当环境温度变化,标准溶液的PH值也随之有所变化;目前大多数PH计没有温度校正功能,影响了PH值的测量精度。Generally, the concentration of the standard solution is the pH value measured at an ambient temperature of 25°C. When the ambient temperature changes, the pH value of the standard solution will also change; most of the current pH meters do not have a temperature correction function, which affects the The measurement accuracy of pH value.

同时,对于不同的标准溶液和待测溶液,PH电极输出的溶液mV值的范围较大,经过运算放大器放大后,一般都在0~±1999.9mV;常规的PH计都采用同一组放大电路进行放大,这样对于一些小信号用大量程转换而降低了分辨率,也影响了低浓度PH值的测量精度。At the same time, for different standard solutions and solutions to be tested, the mV value of the solution output by the pH electrode has a large range. After being amplified by the operational amplifier, it is generally 0 ~ ± 1999.9mV; Amplification, such that for some small signals, the resolution is reduced by using a large range of conversion, and it also affects the measurement accuracy of the low-concentration pH value.

另外,用来标定的标准溶液一般是固定的3种左右,PH计必须获取这些标准溶液的PH值才能进行计算;常规的PH计都是在一点校正和二点校正时手工输入溶液的PH值,这样不但操作使用不便,还可能造成人为误差。In addition, the standard solutions used for calibration are generally fixed about 3 kinds, and the pH meter must obtain the pH value of these standard solutions to calculate; the conventional pH meter is manually input the pH value of the solution during one-point calibration and two-point calibration , which is not only inconvenient to operate and use, but also may cause human error.

技术方案:本发明的目的在于克服传统PH计的上述缺陷,提出一种高精度智能酸度(PH)计及其测量方法,采用如下技术方案:Technical solution: The purpose of the present invention is to overcome the above-mentioned defects of the traditional PH meter, and propose a high-precision intelligent acidity (PH) meter and its measurement method, adopting the following technical solution:

一种高精度智能酸度计,包括单片机电路、A/D转换电路、人机接口电路和电源电路,A/D转换电路和人机接口电路分别与单片机电路连接,其特征在于,A/D转换电路包括温度传感器、PH传感器、第一运算放大器、第二运算放大器、多路模拟开关和A/D转换器,温度传感器、PH传感器的输出分别经第一、第二运算放大器连接至多路模拟开关其中一个通道的多个输入端,所述其中一个通道的输出端与A/D转换器连接,多路模拟开关的另一个通道的输出端连接到第二运算放大器的反相输入端,所述另一个通道的其中两个输入端分别连接不同阻值的电阻,供量程切换,多路模拟开关的地址端与单片机电路连接。A high-precision intelligent acidity meter comprises a single-chip microcomputer circuit, an A/D conversion circuit, a man-machine interface circuit and a power supply circuit, and the A/D conversion circuit and the man-machine interface circuit are respectively connected to the single-chip microcomputer circuit, and is characterized in that the A/D conversion The circuit includes a temperature sensor, a pH sensor, a first operational amplifier, a second operational amplifier, a multi-channel analog switch and an A/D converter, and the outputs of the temperature sensor and the pH sensor are respectively connected to the multi-channel analog switch through the first and second operational amplifiers Multiple input ends of one of the channels, the output end of one of the channels is connected to the A/D converter, and the output end of the other channel of the multi-channel analog switch is connected to the inverting input end of the second operational amplifier, the said Two of the input terminals of the other channel are respectively connected to resistors with different resistance values for range switching, and the address terminals of the multi-channel analog switch are connected to the single-chip microcomputer circuit.

所述高精度智能酸度计的测量方法,其特征在于温度补偿方法,采用温度传感器测量环境温度,对非标准温度的标准溶液进行校正,单片机电路根据不同的温度范围采用不同公式进行计算,得到环境温度下的标准溶液的PH值,具体方法如下:The measurement method of the high-precision intelligent acidity meter is characterized in that the temperature compensation method uses a temperature sensor to measure the ambient temperature, corrects the standard solution at a non-standard temperature, and the single-chip circuit uses different formulas to calculate according to different temperature ranges to obtain the environmental temperature The pH value of the standard solution under the temperature, the concrete method is as follows:

一点校正时:When correcting by one point:

0°C~50°C  PH1=0.0000483t1 2-0.001266t1+4.004……(1)0°C~50°C PH 1 =0.0000483t 1 2 -0.001266t 1 +4.004...(1)

50°C~60°C PH1=0.0000483t1 2-0.001266t1+3.994……(2)50°C~60°C PH 1 =0.0000483t 1 2 -0.001266t 1 +3.994...(2)

其中,PH1表示一点校正标准溶液的测量PH值,t1表示一点校正所测得的环境温度值;Wherein, PH 1 represents the measured pH value of one-point calibration standard solution, and t 1 represents the measured ambient temperature value of one-point calibration;

二点校正时:During two-point calibration:

0°C~50°C  PH2=0.00006875t2 2-0.006311t2+6.979……(3)0°C~50°C PH 2 =0.00006875t 2 2 -0.006311t 2 +6.979...(3)

50°C~60°C PH2=0.0000776t2 2-0.01268t2+9.453……(4)50°C~60°C PH 2 =0.0000776t 2 2 -0.01268t 2 +9.453...(4)

其中,PH2表示二点校正标准溶液的测量PH值,t2表示二点校正所测得的环境温度值。Wherein, PH 2 represents the measured pH value of the two-point calibration standard solution, and t 2 represents the measured ambient temperature value of the two-point calibration.

在进行一点校正和二点校正时,根据PH传感器所测标准溶液的毫伏值,经运算放大器放大后,单片机电路对放大后的毫伏值进行采集,并依据不同标准溶液的毫伏值范围自动识别标准溶液。When performing one-point calibration and two-point calibration, according to the millivolt value of the standard solution measured by the pH sensor, after being amplified by the operational amplifier, the single-chip circuit collects the amplified millivolt value, and according to the millivolt value range of different standard solutions Automatic identification of standard solutions.

有益效果:Beneficial effect:

1、本发明的酸度计采用量程的自动切换,用不同阻值的电阻构成两种不同的反馈电路,与多路模拟开关的2个输入通道连接,单片机通过选择模拟开关通道地址,选择相应的通道,根据PH电极输出的溶液mV值的大小,实现量程范围0~±399.9mV和0~±1999.9mV之间自动切换,避免了小信号大量程转换(俗话说的大秤称小物),提高了小信号的分辨率,提高了低浓度溶液的测量精度。1, the acidity meter of the present invention adopts the automatic switching of measuring range, constitutes two kinds of different feedback circuits with the resistance of different resistance value, is connected with 2 input channels of multi-channel analog switch, single-chip microcomputer selects corresponding analog switch channel address by selecting The channel, according to the mV value of the solution output by the pH electrode, realizes automatic switching between the range of 0~±399.9mV and 0~±1999.9mV, avoiding the conversion of small signals to large ranges (as the saying goes, large scales are called small objects), and improve It improves the resolution of small signals and improves the measurement accuracy of low-concentration solutions.

2、本发明的酸度计,多路模拟开关连接在运算放大器的反馈电路中,多路模拟开关的接通电阻作为运算放大器反馈电阻的一部分,消除了被测信号在模拟开关接通电阻的损耗,提高了测量精度。2. In the acidity meter of the present invention, the multi-channel analog switch is connected in the feedback circuit of the operational amplifier, and the on-resistance of the multi-channel analog switch is used as a part of the feedback resistance of the operational amplifier, which eliminates the loss of the measured signal at the analog switch on-resistance , improving the measurement accuracy.

3、本发明的酸度计采用温度传感器测量环境温度,对非标准温度(25°C)的标准溶液的进行校正,根据不同的温度范围用不同的公式进行计算,得到环境温度下的标准溶液的PH值,以此进行温度补偿,提高了测量精度。3. The acidity meter of the present invention uses a temperature sensor to measure the ambient temperature, corrects the standard solution at a non-standard temperature (25°C), calculates with different formulas according to different temperature ranges, and obtains the standard solution at the ambient temperature. PH value, in order to carry out temperature compensation, improve the measurement accuracy.

4、本发明的酸度计在进行一点校正和二点校正时,根据测得的标准溶液的毫伏(mV)值,自动识别标准溶液的PH值或浓度,无需进行手工输入,减少了工作量,避免了人工操作可能带来的误差,提高了自动化程度。4. When performing one-point calibration and two-point calibration, the acidity meter of the present invention can automatically identify the pH value or concentration of the standard solution according to the measured millivolt (mV) value of the standard solution, without manual input, reducing the workload , avoiding the errors that may be caused by manual operation, and improving the degree of automation.

5、本发明的酸度计及其测量方法大大提高了PH计的的稳定性,能够达到0.001的测量精度。5. The pH meter and its measurement method of the present invention greatly improve the stability of the pH meter and can achieve a measurement accuracy of 0.001.

附图说明: Description of drawings:

图1是本发明专利高精度智能酸度(PH)计的结构图。Figure 1 is a structural diagram of the patented high-precision intelligent acidity (PH) meter of the present invention.

图2是本发明专利的硬件电路图。Fig. 2 is a hardware circuit diagram of the patent of the present invention.

图3是本发明专利PH电极输出的标准溶液PH值的范围示意图。Fig. 3 is a schematic diagram of the scope of the pH value of the standard solution output by the patented pH electrode of the present invention.

具体实施方式 Detailed ways

下面结合附图对本发明做进一步详细阐述:Below in conjunction with accompanying drawing, the present invention is described in further detail:

如图1所示为本发明的高精度智能酸度(PH)计结构图,所述PH计包括单片机电路1、A/D转换电路2、电源电路3、人机接口电路4。电源电路3分别为单片机电路1、A/D转换电路2、人机接口电路4供电。A/D转换电路2和人机接口电路4分别与单片机电路1连接。单片机电路1以一个单片机为核心,用以采集和计算数据。人机接口电路4包括LCD、键盘和蜂鸣器,用以显示,输入信息,报警。A/D转换电路包括温度传感器(测量温度)、PH传感器(测量PH值)、第一运算放大器(对温度传感器的输出信号进行放大)、第二运算放大器(对PH传感器的输出信号进行放大)、多路模拟开关(在单片机的控制下实现信号的传输)和A/D转换器(将模拟信号转换为数字信号供单片机处理)。As shown in FIG. 1 is a structure diagram of a high-precision intelligent acidity (PH) meter of the present invention. The pH meter includes a single-chip microcomputer circuit 1, an A/D conversion circuit 2, a power supply circuit 3, and a man-machine interface circuit 4. The power supply circuit 3 supplies power to the single-chip microcomputer circuit 1, the A/D conversion circuit 2, and the man-machine interface circuit 4 respectively. The A/D conversion circuit 2 and the man-machine interface circuit 4 are connected to the single-chip microcomputer circuit 1 respectively. The single-chip microcomputer circuit 1 uses a single-chip microcomputer as the core to collect and calculate data. The man-machine interface circuit 4 includes LCD, keyboard and buzzer for displaying, inputting information and alarming. The A/D conversion circuit includes a temperature sensor (to measure temperature), a pH sensor (to measure pH value), a first operational amplifier (to amplify the output signal of the temperature sensor), and a second operational amplifier (to amplify the output signal of the pH sensor) , Multi-channel analog switch (realize signal transmission under the control of single-chip microcomputer) and A/D converter (convert analog signal into digital signal for processing by single-chip microcomputer).

本发明的高精度智能酸度(PH)计的电路图如图2所示,人机接口电路4中的LCD12864的RS、R/W、E与单片机电路2的单片机U1(AT89C52)的P1.3,P1.2,P1.1连接,AT89C52的端口P0.0、P0.1、P0.2、P0.3、P0.4、P0.5、P0.6、P0.7和P1.4分别与人机接口电路4中的键盘和蜂鸣器连接,单片机电路2的AT89C52的端口P1.7、P2.7、P2.6、P2.5、P2.4、P2.3、P2.2、P2.1、P2.0、P3.5、P3.4、P3.2和P3.6与A/D转换电路2中A/D转换器U8(7135)的D1、D2、D3、D4、D5、B1、B2、B4、B8、POL、OR、-STB和R/-H相连。A/D转换电路2中还包含由555、电容C9、C8以及滑动变阻器R9、R12组成的时钟电路。The circuit diagram of the high-precision intelligent acidity (PH) meter of the present invention is shown in Figure 2, RS, R/W, E of LCD12864 in the man-machine interface circuit 4 and P1.3 of the single-chip microcomputer U1 (AT89C52) of the single-chip microcomputer circuit 2, P1.2, P1.1 connection, ports P0.0, P0.1, P0.2, P0.3, P0.4, P0.5, P0.6, P0.7 and P1.4 of AT89C52 are connected to people respectively The keyboard and buzzer in the computer interface circuit 4 are connected, and the ports P1.7, P2.7, P2.6, P2.5, P2.4, P2.3, P2.2, P2 of the AT89C52 of the microcontroller circuit 2. 1. P2.0, P3.5, P3.4, P3.2 and P3.6 and D1, D2, D3, D4, D5, B1 of A/D converter U8 (7135) in A/D conversion circuit 2 , B2, B4, B8, POL, OR, -STB and R/-H are connected. The A/D conversion circuit 2 also includes a clock circuit composed of 555, capacitors C9, C8 and sliding rheostats R9, R12.

温度传感器U9(AD590)的信号输出端连接至第一运算放大器M1(LM301)的同相输入端,第一运算放大器M1的输出端连接至多路模拟开关U7(4052)的X通道的输入端X3。PH传感器U11的信号输出端连接至第二运算放大器M2(LM301)的同相输入端,第二运算放大器M2的输出端连接至多路模拟开关U7的X通道的输入端X0和X1。多路模拟开关U7的X通道的输出端X连接至7135的+IN、-IN端,其输出信号经7135转换成数字信号供单片机处理。The signal output terminal of the temperature sensor U9 (AD590) is connected to the non-inverting input terminal of the first operational amplifier M1 (LM301), and the output terminal of the first operational amplifier M1 is connected to the input terminal X3 of the X channel of the multi-channel analog switch U7 (4052). The signal output terminal of the pH sensor U11 is connected to the non-inverting input terminal of the second operational amplifier M2 (LM301), and the output terminal of the second operational amplifier M2 is connected to the input terminals X0 and X1 of the X channel of the multi-channel analog switch U7. The output terminal X of the X channel of the multi-channel analog switch U7 is connected to the +IN and -IN terminals of the 7135, and the output signal is converted into a digital signal by the 7135 for processing by the single-chip microcomputer.

多路模拟开关U7的Y通道输出端Y连接至第二运算放大器M2的反相输入端。多路模拟开关U7的Y通道输入端Y0和Y1分别连接不同阻值的电阻R14(75K)和R15(4.5K)。多路模拟开关U7的地址端A、B分别连接单片机的端口P1.6和P1.5,单片机根据PH电极输出的溶液mV值的大小,选通相应通道,使电阻R14或R15和多路模拟开关的接通电阻形成串联,作为第二运算放大器M2的反馈电阻,一方面可以实现量程范围0~±399.9mV和0~±1999.9mV之间自动切换,另一方面还可以消除被测信号在模拟开关接通电阻的损耗,提高了测量精度。The Y channel output terminal Y of the multi-channel analog switch U7 is connected to the inverting input terminal of the second operational amplifier M2. The Y channel input terminals Y0 and Y1 of the multi-channel analog switch U7 are respectively connected to resistors R14 (75K) and R15 (4.5K) with different resistance values. The address terminals A and B of the multi-channel analog switch U7 are respectively connected to ports P1.6 and P1.5 of the single-chip microcomputer, and the single-chip microcomputer selects the corresponding channel according to the mV value of the solution output by the pH electrode, so that the resistance R14 or R15 and the multi-channel analog The on-resistance of the switch forms a series connection, and as the feedback resistance of the second operational amplifier M2, on the one hand, it can realize the automatic switching between the range of 0-±399.9mV and 0-±1999.9mV, and on the other hand, it can also eliminate the signal under test. The loss of the on-resistance of the analog switch improves the measurement accuracy.

1、测量方法1. Measurement method

1.1、预置1.1, preset

PH0=7.593    SLOPE0=0.19841t+54.195PH 0 =7.593 SLOPE 0 =0.19841t+54.195

PH0表示预置PH值,SLOPE0表示预置斜率。PH 0 means the preset pH value, and SLOPE 0 means the preset slope.

Figure BDA00002162506400041
Figure BDA00002162506400041

1.2、一点校正1.2. One-point correction

采样mV10显示PH10=PH0-mV10/Slope0 Sampling mV 10 shows PH 10 = PH 0 -mV 10 /Slope 0

mV10表示一点校正标准溶液的测量瞬时毫伏值,mV 10 represents the measured instantaneous millivolt value of a point calibration standard solution,

PH10表示一点校正标准溶液的测量瞬时PH值。PH 10 represents the measured instantaneous pH value of a one-point calibration standard solution.

稳定条件:按下一点校正键后开始计时30s,要求:Stable conditions: start timing for 30s after pressing a point correction key, requirements:

①30s后的第一个10s内mV10变化小于0.5mV,若成立记下最后的mV10值,并转稳定状态,此时mV1=mV10①In the first 10s after 30s, the change of mV 10 is less than 0.5mV. If it is established, record the last mV 10 value and turn to a stable state. At this time, mV 1 =mV 10 .

mV1表示一点校正标准溶液的测量毫伏值。mV 1 represents the measured millivolt value of a one-point calibration standard solution.

②若第一个10s稳不下来,再延时按上面的方法判断,记下最后的mV10值,此时mV1=mV10 ②If the first 10s cannot be stabilized, then delay the judgment according to the above method, and write down the last mV 10 value, at this time mV 1 =mV 10

③若30″内还稳定不下来,显示出错信息③If it cannot be stabilized within 30″, an error message will be displayed

稳定后,单片机根据温度传感器所测环境温度(即所测标准溶液的温度)从下面的公式确定最终显示的PH1值:After stabilization, the single-chip microcomputer determines the final displayed PH 1 value from the following formula according to the ambient temperature measured by the temperature sensor (that is, the temperature of the measured standard solution):

0°C~50°C  PH1=0.0000483t1 2-0.001266t1+4.004……(1)0°C~50°C PH 1 =0.0000483t 1 2 -0.001266t 1 +4.004...(1)

50°C~60°C PH1=0.0000483t1 2-0.001266t1+3.994……(2)50°C~60°C PH 1 =0.0000483t 1 2 -0.001266t 1 +3.994...(2)

最后记存(PH1,mV1);t1 last store (PH 1 , mV 1 ); t 1

PH1表示一点校正标准溶液的测量PH值,PH 1 represents the measured pH value of a one-point calibration standard solution,

t1表示一点校正所测得的环境温度值。t 1 represents the ambient temperature value measured by one-point correction.

1.3、二点校正1.3. Two-point calibration

采样mV20显示PH20=PH0-mV20/Slope0 Sampling mV 20 shows PH 20 = PH 0 -mV 20 /Slope 0

mV20表示二点校正标准溶液的测量瞬时毫伏值,mV 20 represents the measured instantaneous millivolt value of the two-point calibration standard solution,

PH20表示二点校正标准溶液的测量瞬时PH值。PH 20 represents the measured instantaneous pH value of the two-point calibration standard solution.

稳定条件:按下二点校正键后开始计时30s,要求:Stable conditions: start timing 30s after pressing the two-point correction key, requirements:

①30s后的第一个10s内mV20变化小于0.5mV,若成立记下最后的mV20值,并转稳定状态,此时mV2=mV20 ①In the first 10s after 30s, the change of mV 20 is less than 0.5mV. If it is established, record the last mV 20 value and turn to a stable state. At this time, mV 2 =mV 20

mV2表示二点校正标准溶液的测量毫伏值。mV 2 represents the measured millivolt value of the two-point calibration standard solution.

②若第一个10s稳不下来,再延时按上面的方法判断,记下最后的mV10值,此时mV2=mV20 ②If the first 10s cannot be stabilized, judge the delay according to the above method, and record the last mV 10 value, at this time mV 2 =mV 20

③若30″内还稳定不下来,显示出错信息③If it cannot be stabilized within 30″, an error message will be displayed

稳定后,单片机根据温度传感器所测环境温度(即所测标准溶液的温度)从下面的公式确定最终显示的PH2值:After stabilization, the single-chip microcomputer determines the final displayed PH 2 value from the following formula according to the ambient temperature measured by the temperature sensor (that is, the temperature of the measured standard solution):

0°C~50°C   PH2=0.00006875t2 2-0.006311t2+6.979……(3)0°C~50°C PH 2 =0.00006875t 2 2 -0.006311t 2 +6.979...(3)

50°C~60°C  PH2=0.0000776t2 2-0.01268t2+9.453……(4)50°C~60°C PH 2 =0.0000776t 2 2 -0.01268t 2 +9.453...(4)

稳定后记存(PH2,mV2);t2 Store after stabilization (PH 2 , mV 2 ); t 2

PH2表示二点校正标准溶液的测量PH值,PH 2 represents the measured pH value of the two-point calibration standard solution,

t2表示二点校正所测得的环境温度值。t 2 represents the ambient temperature value measured by two-point calibration.

1.4、计算斜率1.4. Calculate the slope

斜率 Slope = m V 2 - m V 1 PH 2 - PH 1 slope Slope = m V 2 - m V 1 pH 2 - pH 1

要求SLOPE值在如下范围内:The SLOPE value is required to be within the following range:

0.8×(0.19841t1+54.195)<|SLOPE|<1.1×(0.19841t1+54.195)0.8×(0.19841t 1 +54.195)<|SLOPE|<1.1×(0.19841t 1 +54.195)

否则显示出错。Otherwise an error is displayed.

Slope表示PH电极测量的斜率。Slope indicates the slope measured by the pH electrode.

1.5、测量1.5. Measurement

采样mVx Sampling mV x

mVx0表示待测溶液的测量瞬时毫伏值。mV x0 represents the measured instantaneous millivolt value of the solution to be tested.

mVx表示待测溶液的测量毫伏值。mV x represents the measured millivolt value of the solution to be tested.

稳定条件:按下测量键后开始计时30s,要求:Stable conditions: start timing 30s after pressing the measurement key, requirements:

①30s后的第一个10s内mVx0变化小于0.5mV,若成立记下最后的mVx0值,并转稳定状态,此时mVx=mVx0 ①In the first 10s after 30s, the change of mV x0 is less than 0.5mV. If it is established, record the last value of mV x0 and turn to a stable state. At this time, mV x =mV x0

②若第一个10s稳不下来,再延时按上面的方法判断,记下最后的mVx0值,此时mVx=mVx0 ②If the first 10s cannot be stabilized, judge the delay according to the above method, and record the final mV x0 value, at this time mV x =mV x0

③若30″内还稳定不下来,显示出错信息③If it cannot be stabilized within 30″, an error message will be displayed

计算:a)如果t2=t1(相等状态维持连续0.5s以上算相等)Calculation: a) If t 2 =t 1 (the equal state remains equal for more than 0.5s)

SlopeSlope == mm VV 22 -- mm VV 11 PHpH 22 -- PHpH 11

PHpH xx == PHpH 11 ++ mm VV xx -- mm VV 11 SlopeSlope

最后显示PHx值。Finally the PH x value is displayed.

PHx表示待测溶液的测量PH值PH x represents the measured pH value of the solution to be tested

注:如PHx<0 or PHx>14显示出错信息Note: If PH x <0 or PH x >14, an error message will be displayed

b)如t2≠t1 b) If t 2 ≠t 1

根据t1和t2从如下公式计算PHx From t 1 and t 2 calculate PH x from the following formula

mm VV 11 &prime;&prime; == (( 7.7937.793 -- PHpH 11 &prime;&prime; )) (( 0.198410.19841 tt 22 ++ 54.19554.195 )) (( 7.7937.793 -- PHpH 11 )) (( 0.198410.19841 tt 11 ++ 54.19554.195 )) mm VV 11

mm VV 22 &prime;&prime; == (( 7.7937.793 -- PHpH 22 &prime;&prime; )) (( 0.198410.19841 tt 22 ++ 54.19554.195 )) (( 7.7937.793 -- PHpH 22 )) (( 0.198410.19841 tt 11 ++ 54.19554.195 )) mm VV 22

SlopeSlope &prime;&prime; == mm VV 22 &prime;&prime; -- mm VV 11 &prime;&prime; PP Hh 22 &prime;&prime; PP Hh 11 &prime;&prime;

PHpH xx == PHpH 11 &prime;&prime; ++ mm VV xx -- mm VV 11 &prime;&prime; SlopeSlope &prime;&prime;

1.6出错指示1.6 Error indication

①Er1:标准渗液超范围①Er 1 : Standard seepage out of range

②Er2:二点渗液同一点渗液②Er 2 : Two points of exudate and one point of exudate

③Er3:定标和测量时60s稳不下来③Er 3 : 60s cannot be stabilized during calibration and measurement

④Er4:PH测量超出0~14④Er 4 : PH measurement exceeds 0~14

mV测量超出±1999.9mVmV measurement exceeds ±1999.9mV

⑤Er5:在校准和测量情况下温度超出(0~60°C)⑤Er 5 : Temperature exceeds (0~60°C) during calibration and measurement

⑥Er6:Er6电极斜率超范围⑥Er 6 : Er 6 electrode slope out of range

⑦Er7:Er7非法操作⑦Er 7 : Er 7 illegal operation

2、标准溶液的自动识别方法2. Automatic identification method of standard solution

如图3所示为本发明专利PH电极输出的标准溶液PH值的范围示意图。常用的标准溶液主要有三种:PH=10,PH=6和PH=4,根据环境温度变化的不同,PH电极测得的溶液毫伏值的范围如下:Figure 3 is a schematic diagram of the scope of the pH value of the standard solution output by the patented pH electrode of the present invention. There are three commonly used standard solutions: PH=10, PH=6 and PH=4. According to the change of the ambient temperature, the range of the millivolt value of the solution measured by the pH electrode is as follows:

PH=10的标准液的毫伏值的范围为-156mV~-36mV;The range of millivolt value of standard solution with PH=10 is -156mV~-36mV;

PH=6的标准液的毫伏值的范围为-20mV~100mV;The range of millivolt value of the standard solution with PH=6 is -20mV~100mV;

PH=4的标准液的毫伏值的范围为150mV~270mV;The millivolt value of the standard solution with PH=4 ranges from 150mV to 270mV;

用运算放大器放大5倍,单片机进行采集,根据采集到的标准液的毫伏值mVX来判别标准液:Use the operational amplifier to amplify 5 times, and the single-chip microcomputer to collect, and judge the standard solution according to the millivolt value mVX of the collected standard solution:

-780mV≤mVX≤-180mV,为PH=10的标准液;-780mV≤mVX≤-180mV, which is the standard solution of PH=10;

-100mV≤mVX≤500mV,为PH=6的标准液;-100mV≤mVX≤500mV, it is the standard solution of PH=6;

750mV≤mVX≤1375mV,为PH=6的标准液;750mV≤mVX≤1375mV, which is the standard solution of PH=6;

其余范围作出错处理。The remaining ranges are treated as errors.

Claims (6)

1.一种高精度智能酸度计,包括单片机电路、A/D转换电路、人机接口电路和电源电路,A/D转换电路和人机接口电路分别与单片机电路连接,其特征在于,A/D转换电路包括温度传感器、PH传感器、第一运算放大器、第二运算放大器、多路模拟开关和A/D转换器,温度传感器、PH传感器的输出分别经第一、第二运算放大器连接至多路模拟开关其中一个通道的多个输入端,所述其中一个通道的输出端与A/D转换器连接,多路模拟开关的另一个通道的输出端连接到第二运算放大器的反相输入端,所述另一个通道的其中两个输入端分别连接不同阻值的电阻,供量程切换,多路模拟开关的地址端与单片机电路连接。 1. A high-precision intelligent acidity meter comprises a single-chip microcomputer circuit, an A/D conversion circuit, a human-machine interface circuit and a power supply circuit, and the A/D conversion circuit and the human-machine interface circuit are connected with the single-chip microcomputer circuit respectively, and it is characterized in that A/D The D conversion circuit includes a temperature sensor, a pH sensor, a first operational amplifier, a second operational amplifier, a multi-channel analog switch and an A/D converter, and the outputs of the temperature sensor and the pH sensor are respectively connected to the multiple channel via the first and second operational amplifiers. A plurality of input terminals of one of the channels of the analog switch, the output terminal of one of the channels is connected to the A/D converter, and the output terminal of the other channel of the multi-channel analog switch is connected to the inverting input terminal of the second operational amplifier, Two of the input terminals of the other channel are respectively connected to resistors of different resistances for range switching, and the address terminals of the multi-channel analog switch are connected to the single-chip microcomputer circuit. 2.如权利要求1所述的高精度智能酸度计,其特征在于PH传感器输出的信号经第二运算放大器放大后,接入多路模拟开关的X通道输入端X0和X1。 2. The high-precision intelligent acidity meter according to claim 1, wherein the signal output by the pH sensor is amplified by the second operational amplifier, and then connected to the X channel input terminals X0 and X1 of the multi-channel analog switch. 3.如权利要求1所述的高精度智能酸度计,其特征在于温度传感器输出的信号经第一运算放大器放大后,接入多路模拟开关的X通道输入端X3。 3. The high-precision intelligent acidity meter according to claim 1, characterized in that the signal output by the temperature sensor is amplified by the first operational amplifier, and then connected to the X channel input terminal X3 of the multi-channel analog switch. 4.如权利要求1~3任一所述的高精度智能酸度计,其特征在于多路模拟开关的Y通道的输出端连接到第二运算放大器的反相输入端,其输入端Y0和Y1分别连接不同阻值的电阻。 4. The high-precision intelligent acidity meter as claimed in any one of claims 1 to 3, wherein the output terminal of the Y channel of the multi-channel analog switch is connected to the inverting input terminal of the second operational amplifier, and its input terminals Y0 and Y1 Connect resistors with different resistance values. 5.如权利要求1所述高精度智能酸度计的测量方法,其特征在于温度补偿方法,采用温度传感器测量环境温度,对非标准温度的标准溶液进行校正,单片机电路根据不同的温度范围采用不同公式进行计算,得到环境温度下的标准溶液的PH值,具体方法如下: 5. the measuring method of high-precision intelligent acidity meter as claimed in claim 1, it is characterized in that temperature compensation method, adopt temperature sensor to measure ambient temperature, the standard solution of non-standard temperature is corrected, single-chip microcomputer circuit adopts different according to different temperature ranges The formula is calculated to obtain the pH value of the standard solution at ambient temperature, and the specific method is as follows: 一点校正时: When correcting by one point: 0                                                
Figure 271252DEST_PATH_IMAGE002
~50
Figure 814491DEST_PATH_IMAGE002
   
0
Figure 271252DEST_PATH_IMAGE002
~50
Figure 814491DEST_PATH_IMAGE002
50
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~60
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50
Figure 817135DEST_PATH_IMAGE002
~60
Figure 569190DEST_PATH_IMAGE002
其中,PH 1表示一点校正标准溶液的测量PH值,t 1表示一点校正所测得的环境温度值; Wherein, PH 1 represents the measured pH value of one-point calibration standard solution, and t 1 represents the measured ambient temperature value of one-point calibration; 二点校正时: During two-point calibration: 0
Figure 409419DEST_PATH_IMAGE002
~50  
Figure 87317DEST_PATH_IMAGE008
0
Figure 409419DEST_PATH_IMAGE002
~50
Figure 87317DEST_PATH_IMAGE008
50
Figure 205315DEST_PATH_IMAGE002
~60  
50
Figure 205315DEST_PATH_IMAGE002
~60
其中,PH 2表示二点校正标准溶液的测量PH值,t 2表示二点校正所测得的环境温度值。 Wherein, PH 2 represents the measured pH value of the two-point calibration standard solution, and t 2 represents the measured ambient temperature value of the two-point calibration.
6.如权利要求5所述高精度智能酸度计的测量方法,其特征在于在进行一点校正和二点校正时,根据PH传感器所测标准溶液的毫伏值,经运算放大器放大后,单片机电路对放大后的毫伏值进行采集,并依据不同标准溶液的毫伏值范围自动识别标准溶液。 6. the measuring method of high-precision intelligent acidity meter as claimed in claim 5 is characterized in that when carrying out one-point correction and two-point correction, according to the millivolt value of the standard solution measured by the pH sensor, after being amplified by the operational amplifier, the single-chip microcomputer circuit Collect the amplified millivolt value, and automatically identify the standard solution according to the millivolt value range of different standard solutions.
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CN110186987A (en) * 2019-06-27 2019-08-30 上海三信仪表厂 A kind of general 25 degree of translation methods of solution pH value
CN110440937A (en) * 2019-08-13 2019-11-12 苏州德瑞芬诺环境科技有限公司 A kind of pH analyzer with temperature detection and warning function
CN115184427A (en) * 2022-09-09 2022-10-14 中大智能科技股份有限公司 Temperature compensation experiment method applied to pH sensor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4940551A (en) * 1989-05-19 1990-07-10 Riggs James B Method for pH control
CN2224420Y (en) * 1993-08-21 1996-04-10 中国矿业大学 PH/potential intelligent analysis and test instrument

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4940551A (en) * 1989-05-19 1990-07-10 Riggs James B Method for pH control
CN2224420Y (en) * 1993-08-21 1996-04-10 中国矿业大学 PH/potential intelligent analysis and test instrument

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
SANDRA W.BISHNOI,CHRISTOPHER J.ROZELL ETAL: "All-Optical Nanoscale pH Meter", 《NANO LETTERS》 *
易军,黄蓓: "酸度计的校正", 《计量与测试技术》 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104330445A (en) * 2013-07-22 2015-02-04 霍尼韦尔国际公司 APPARATUS AND METHOD FOR COMPENSATING pH MEASUREMENT ERRORS DUE TO PRESSURE AND PHYSICAL STRESSES
CN106596887A (en) * 2016-12-06 2017-04-26 中国地质调查局水文地质环境地质调查中心 Deep aquifer multiparameter in-situ monitoring apparatus and method thereof
CN110186987A (en) * 2019-06-27 2019-08-30 上海三信仪表厂 A kind of general 25 degree of translation methods of solution pH value
CN110186987B (en) * 2019-06-27 2022-03-08 上海三信仪表厂 Universal solution PH value 25 degree conversion method
CN110440937A (en) * 2019-08-13 2019-11-12 苏州德瑞芬诺环境科技有限公司 A kind of pH analyzer with temperature detection and warning function
CN115184427A (en) * 2022-09-09 2022-10-14 中大智能科技股份有限公司 Temperature compensation experiment method applied to pH sensor

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