We can think of it as a sort of shorthand for specifying the concentration of protons (H+ ions) in (usually aqueous) solution. Sorensen defined pH = -log[H+]. In water, pH values from 0 (very acidic) to 14 (very basic) are possible. Thus pH 7, being right in the middle of the range, is neutral, that is, neither acidic nor basic. There are two tricky things about this scale: it’s nonlinear and it seems “to go the wrong way”. Both of these odd features stem from the fact that pH involves logarithms. First of all, a negative logarithm indicates an inversion or reciprocal of a number; that is why the scale seems “to go the wrong way.” Also because of logarithms, the numbers seem much smaller.

The pH is a scale of numbers that simplifies manipulation, calculation, and discussions involving the wide range of hydrogen ions in a solution. Determination of pH is a determination of emf (voltage) difference in a pH cell. pH is dependent upon temperature; a temperature compensator varies the instrument definition of a pH unit from 54.20 mV to 66.10 mV at 60C°.

A pH meter consists of an electrode to sense pH, a reference electrode to complete the circuit while not affecting the pH measurement, an electronics module to link the electrode to the readout, and a display unit, which could be a meter or a computer screen. Some pH meters also have a third electrode to sense the temperature, in order to compensate for thermal effects. Often the electrodes are packaged into a “combination electrode” which is more convenient to use. The most frequent cause of pH meter malfunction is poorly-maintained electrodes.

In modern chemistry the “p” (“negative log of”) notation has been extended to other species. Thus a chemist may use pS-, pNO2-, pNa+, and even p(urea). So-called ion-selective electrodes have been developed to measure all of those and many more.

In order to measure a pH value, a measuring electrode (pH electrode) and a reference electrode are needed. In many cases, a combination electrode, housing both measuring and reference elements, is used.

Successful pH measurement can only be achieved by choosing the correct system to meet the demands of the sample under examination. As well as the correct apparatus, a supply of suitable reagents is vital.

For optimal pH measurement, the correct electrode must first be selected. The following criteria must be considered: Chemical composition, homogeneity, temperature, pH range, container size (length and width restrictions). The choice becomes particularly important for non-aqueous, low conductivity, protein-rich and viscous samples where general purpose glass electrodes are subject to various error sources.

The response time and accuracy of an electrode is dependant upon a number of factors. Measurements at extreme pH values and temperatures, or low conductivity may take longer than those of aqueous solutions at room temperature with a neutral pH. The accuracy of pH readings will depend upon continued maintenance of the electrode, as well as experimental conditions such as temperature, clean or fresh buffer solutions and state of the sample. A pH electrode is characterised by its zero point and its slope, and a two point calibration is chosen for greater precision.

Since pH electrodes have limited lives, it is important to keep one or more spare electrodes available for replacement. An important aspect of the performance of any spare pH electrode is that it will it work when you need it. Electrodes supplied in soaker storage bottles with special soaker solutions have longer shelf lives than those supplied dry, with small caps or dry stored after use. The special solution in soaker bottles provides an environment that maintains pH glass hydration in an acidic environment as well as keeping the reference junction wet and communicating.

New pH Electrode! – Patent

A new type of pH electrode has been developed which uses a solid-electrolyte(No liquid-electrolyte, No gel-electrolyte) resistant gel material that is saturated with KCl.

Successful pH measurement can only be achieved by choosing the correct system to meet the demands of the sample under examination.

Successful pH measurement can only be achieved by choosing the correct system to meet the demands of the sample under examination.

• -Quickly response (within five second), stability and resisting interferon
• -Strong anti-interference ability; it is not easy to be polluted and blocked; long life.
• -The reference system is filled with the high polymer; convenient use; it is unnecessary to refilling electrolyte.

[The overwhelming technology of LOTUS PROSUMING MANAGEMENT]

An element that influence on the standard potential is insoluble salt crust blocking sand core. It is made from AgCl powder which release Ag ion to combine with water to be measured. Another element can also influence on the standard potential. The water to be measured will flow into the standard water by reverse osmosis, changing the density of it. Our patented technology is not subject to these elements, different from other PH electrodes.

We use double salt bridge designed for the standard electrode to measure water polluted with heavy metal, sulfides, or tris buffer solution. AgCl is insulated by thin glass so that it won’t be released to sand core, and formulate salt crust. Solid standard gel cannot be diluted from, or polluted by the water to be measured.

The PH electrodes of Lotus Prosuming Management provide patented technology to lengthen the life span of sensors, and stabilize their potentials.

[เทคโนโลยีที่เหนือกว่าของ LOTUS PROSUMING MANAGEMENT]

Ag อิออนถูกทำให้แยกออกจากกันในผง AgCl สารละลายมาตรฐานในอิเล็กโทรด และไปรวมกับอิออนที่มีประจุไฟฟ้าลบบางส่วนของสารละลายที่ใช้วัดค่า แล้วสาร (salt crust) ก็ถูกปรับทำให้ขัดขวางส่วนต่างๆ ของ sand core สิ่งนี้คือปัจจัยที่ส่งผลต่อศักดิ์ไฟฟ้ามาตรฐาน และสารละลายที่ใช้วัด กลับซึมเข้าสารละลายมาตรฐาน เลยทำให้สารละลายมาตรฐานเปลี่ยนแปลง เป็นสิ่งที่ทำให้ส่งผลกระทบต่อศักดิ์ไฟฟ้ามาตรฐานจากทั้งสองปัจจัยเหล่านี้ ปกติอิเล็กโทรดpH ทั้งหมดมีลักษณะแบบนี้ แต่เทคโนโลยีที่ได้รับลิขสิทธิ์ของบริษัทเรานั้นมีความพิเศษมาก

ตามแผนผังมาตรฐานอิเล็กโทรด double salt bridgeนั้น สามารถวัดสารละลายที่ถูกปนเปื้อนได้ตั้งแต่ซัลไฟด์, โลหะหนักและสารละลายบัฟเฟอร์ tris สิ่งนี้นั้น AgCl ไหลไปท่วมหลอดแก้ว ทำให้ Agอิออนไม่ถูกแยกออกจากส่วนต่างๆ ของ sand core เพราะ salt crust ไม่ได้ถูกปรับเปลี่ยน และ gel มาตรฐานที่เป็นรูปของแข็งไม่ได้ถูกทำให้เจือจางหรือไม่ได้ถูกทำให้ปนเปื้อนตั้งแต่ใช้วัดสารละลาย

อิเล็กโทรดpH ของบริษัทของเรานั้น เนื่องจากเป็นเทคโนโลยีที่ได้รับลิขสิทธิ์ ยืดอายุการใช้งานของเซ็นเซอร์และสามารถทำศักดิ์ไฟฟ้าของเซ็นเซอร์มีเสถียรภาพได้

[로터스프로슈밍매니지먼트의 압도적인 기술]

기준 전위에 영향을 미치는 인자는, 전극 내 기준액 AgCl 분말에서 Ag이온이 유리되고 측정 대상 용액의 일부 음이온과 결합하여 불용해성의 물질(salt crust)이 형성되어 sand core부위를 막아 버리는 것입니다. 또한 측정 대상 용액이 역 삼투로 기준액에 스며들어 기준액의 농도를 변화시키는데, 이 두 가지 인자로 기준 전위에 영향을 끼치게 됩니다. 보통의 모든 pH 전극이 이러한 형태이지만 폐사의 특허받은 기술은 매우 독특합니다.

Double salt bridge인 기준 전극 설계로는 황화물, 중금속 또는 tris 완충액으로부터 오염된 용액을 측정할 수 있습니다. 이것은 AgCl이 가는 유리관에 휩싸여 Ag이온이 sand core 부위로 유리되지 않아 salt crust가 형성되지 않기 때문이며 고체 상태인 기준 gel이 측정 대상 용액으로 부터 희석되거나 오염되지 않기 때문입니다.
로터스프로슈밍매니지먼트의 pH전극은 이러한 특허 기술로 인해서 센서의 수명을 연장하며 센서의 전위를 안정적으로 할 수 있는 것입니다.