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Finally! An accurate alternative to pH strips. Can be used to measure saliva and urine.
(click here for more information on how to test saliva and urine)

Features:

• Non-glass, store dry sensor
• Convenient one point calibration
• Waterproof
• Fast response time
• Measure samples as small as one drop
• Retains calibration after shut off
• Replaceable reference electrode
• Automatic temperature compensation (ATC)
• Easy-to-read LCD display
• Over 200 hour life on two watch batteries
• Automatic power off
• Error messages alert you to low battery or incorrect calibration
• 1, 2, or 3 point calibration (Model IQ125)
• Automatic buffer recognition (Model IQ125)

*Who is IQ Scientific Instruments?
*pHrequently asked questions about ISFET pH technology

The IQ120 and IQ125 compact, waterproof non-glass pH meters are not designed to be disposable- they are designed to last. They feature advanced ISFET silicon chip pH sensors that provide stable readings in seconds. Only 5 ½" long, these ISFET meters fit right into your pocket. The virtually unbreakable ISFET sensors eliminate the problems of delicate glass sensors that are found on other pocket-sized pH meters. The silicon chip ISFET sensors store dry and need no maintenance. A toothbrush and detergent are all you need to clean dirty sensor surfaces.

Use the Model IQ120 pH meter with convenient one-point calibration for routine pH testing. The Model IQ125 Professional pH meter features automatic buffer recognition and one-point, two-point or three-point calibration for high accuracy over a wide range of pH values. Both pH meter models have automatic temperature compensation for increased accuracy.

The miniLab^TM pocket-sized pH meters come with two replaceable watch batteries that provide over 200 hours of use. An automatic power off feature conserves energy and error messages alert you to a low battery condition or incorrect calibration. Other features include a replaceable reference electrode, retention of calibration after shutoff and the ability to measure samples as small as a single drop.

IQ Scientific Instruments is a privately held California corporation founded in 1995 with headquarters in Carlsbad, California (just north of San Diego). The company was founded to develop, manufacture and market highly advanced silicon chip sensors for medical, laboratory and industrial pH applications. The company holds a commanding lead in silicon chip sensor technology and has established business relationships with the world’s top scientific instrumentation and marketing companies.

IQ Scientific Instruments has assembled a unique and talented team of individuals with educational and product development backgrounds that address the critical disciplines necessary for successfully commercializing its technology. If one had to pick three important items that separates us from the rest of the pack, these items would be:

What does ISFET stand for?
ion-sensitive field-effect transistors

Used with other manufacturer's meters?
No. The signal from the non-glass silicon chip ISFET sensor is different from conventional glass electrodes and special electronics are required to interpret the signal. The IQ System’s meter and ISFET probe work together as a unit. Unlike traditional glass electrodes, there is no maintenance of the probe. It is ready when and where you are!

Life expectancy?
The non-glass electrode stores dry which increases the expected life of the probe however the life of a non-glass ISFET probe is dependent upon the user’s application and reasonable care. With most applications, a user should expect a probe to perform to specifications for about 15,000 or more samplings, or approximately 9 to 15 months. In applications with intermittent usage, coupled with appropriate cleaning and storage, probes have lasted over five years.

Battery?
The IQ handheld and benchtop pH systems use a standard 9V alkaline battery. The miniLab pH series uses two watch-type button batteries. These batteries lasts for over 200 hours of pH testing. AC adapters are available for the 9V models.

Clean the probe?
The ISFET probe is very easy to keep clean. Normally, rinsing the probe in deionized water then wiping dry with a soft towel or tissue is sufficient. The non-glass probe can also be cleaned with a toothbrush and mild detergent. If food particles, grease, fat or other material covers the sensor, a wooden toothpick and a drop of methanol can be used to gently clean the non-glass sensor itself. If food or other material is allowed to dry on the probe tip, the stainless steel probe can be permanently damaged.

Used in food?
The non-glass stainless steel ISFET probe design allows the probe to be used directly in food processing without contamination as defined by the U.S. Food and Drug Administration.

In-line or process control applications?
The laboratory-style stainless steel pH probes are optimized for momentary pH testing. The probes are not designed for long-term immersion or in-line applications. We do have both threaded Kynar and Stainless Steel in-line probes designed to work with our IQ500 processLab Controller/Analyzer.

Low ionic strength samples? (This question is asked because typically glass electrodes have not shown very good response in low ionic strength solutions)
As the ionic strength of a solution decreases, any pH measurement technology will demonstrate declining response capabilities. However, since IQ Scientific Instruments’ silicon chip sensor relies on surface effects rather than membrane diffusion effects to obtain a reading, the performance of the silicon chip sensor will be as, if not more effective, than glass electrodes. Low ionic strength samples are a difficult application for any type of pH electrode. A gentle stirring action with the probe during measurement will help to achieve a stable reading. Low Ionic Strength (LIS) probes are available in the PH06-SS and PH07-SS models.

Temperature range?
The reading range of the IQ Systems is -5 to 105 °C. To realized the design life of the probe, it is recommended that you try to limit sample temperatures to less than 60° C if possible. Using the probes above 60 °C reduces the useful life.

Materials that harm ISFET electrodes?
Hydrofluoric acid (HF) and strong abrasives will harm the ISFET electrodes. Solvents such as acetone, toluene, methylene chloride, etc., may damage the chemical-resistant epoxy at the probe tip with extended use.

Use bleach to decontaminate the electrodes?
Yes. Soak electrodes for a maximum of 3 to 4 minutes in a 0.5% sodium hypochlorite solution (a 10 to 1 dilution of deionized water to laundry bleach). Then rinse the electrode well with deionized water. DO NOT SOAK YOUR PROBES FOR EXTENDED PERIODS IN THIS SOLUTION. If soaked for extended periods (such as overnight) the bleach solution may etch the chemical resistant epoxy coating at the probe tip and the probe will be permanently damaged.

Clean protein build up?
Use bleach solution as described above. Also, protein can be removed by soaking in a solution of 1% pepsin in 0.1 M HCl for 15-30 minutes.

pH protein solutions in Tris·HCl buffers?
The ISFET electrodes can be used to measure proteins in a Tris-HCl buffer if the probe is routinely cleaned with bleach and restandardized.

How rugged?
The handheld field meter is encased in a shock-resistant holster and is engineered to withstand a ten-foot drop onto concrete without damage. All meters have a membrane keypad and are water-resistant, i.e. splashes and wet hands. The handheld field meter carries an IP rating of 65. The probes are non-glass solid-state electrodes manufactured from 316-grade stainless steel which resist corrosion, bending and breaking.

How small a sample?
The micro probes require an approximate 2mm immersion depth to obtain a reading. An interesting, non-published fact, however, is that the sensor and the reference junction on the general purpose slant tip probe is recessed an approximate 1mm into the chemical resistant resin so as to prevent surface abrasion. If you turn the probe upside down so as to place the slant tip surface in a horizontal position, you will observe an approximate 1µl well created by the recessed chip and juxtaposition reference junction. You can actually obtain a reading on a single drop of fluid by dropping it into this well, covering both the "fet" sensor and the reference junction.

pH reading?
IQ Scientific Instruments’ ISFETs, referred to as "FET" sensors, are silicon chips that have several proprietary layers selectively deposited on a silicon substrate. The final layer has an affinity only for hydrogen ions. Hydrogen ions determine pH. The quantity of hydrogen ions at or near the sensor surface causes an electrical effect that can be detected and measured by the appropriate instrumentation, thus pH is then very precisely derived.

Technical explanation.
The FET consists of a silicon semiconductor substrate with two electrical contacts (source and drain) a small distance apart. Deposited on the substrate between the source and drain is a silicon electrical insulator. Hydrogen ions at or near the surface of the insulator will cause a variable voltage potential between the insulator and the underlying semiconductor material between the source and drain. The variable voltage potential will be proportional to the relative concentration of hydrogen ions in the sample solution. The pH can then be derived from this voltage to a very high level of accuracy.

Warranty?
Meters are warranted for three years; ISFET stainless steel probes for six months. IQ120/125 miniLabs ISFET meters are warranted for one year. Details of the warranty, restrictions, cautions, etc., can be addressed at the time of inquiry or purchase.

Buyers?
IQ Systems are everywhere! IQ Systems are in service in colleges and universities around the nation, in factories, laboratories, bakeries, dairies, wastewater treatment plants, oil drilling platforms, the list goes on and on. When and where a person needs to reliably measure pH and desires non-glass ISFET probes, I.Q. systems are there. In 1998, IQ Systems were subjected to a stringent testing cycle associated with the "CE” mark needed for European sales. The systems passed with shining colors and are now marketed worldwide.

Tech Support?
IQ Scientific maintains full-time tech support staff and a toll-free 800 number for customers to use when technical help or assistance is needed. We take whatever time is needed to solve your concerns with our products and to assure you that IQ Scientific stands behind their products 100%. You won’t be disappointed in service after a sale.

Approved by EPA?
The EPA does not approve specific instrumentation. This government agency does however review manufacturer’s product specifications to see if EPA's defined testing protocols can be adequately performed with the technology and instrumentation. The EPA testing laboratory in Cleveland, Ohio has reviewed the specifications for I.Q. instrumentation and has issued no deficiencies in meeting currently approved EPA pH testing protocols.

Sizes?
IQ Systems’ general-purpose non-glass stainless steel ISFET probes are approximately the same diameter as glass electrodes; ISFET micro probes have a much smaller barrel suitable for test tubes, NMR tubes, etc. The general-purpose probes are approximately 15cm in length; the micro probes are approximately 20cm in length (stainless steel portion). Micro probes constructed for NMR tube applications are approximately 25cm (10 inches) in length. Custom probes of varying lengths or probes with varying cord lengths can be ordered at an additional cost.

Compensate for temperature?
The handheld field meter’s probes have a medical-grade thermistor embedded in the tip that serves to automatically compensate the pH reading for temperature. The IQ240 system incorporates a temperature sensor as an integral part of the ISFET thereby providing for the highest accuracy (parallel tracking with no lag time) of pH and temperature.

Applications to avoid:

Avoid long-term immersion. The system is designed for momentary tests in liquids or semi-solids. Do not use the probe for continuous measurement or in-line use. Do not keep the probe stored in solution. Always store the probe dry.

Avoid abrasive slurries or other solutions that could physically damage the surface of the sensor.

Avoid the following chemicals such as Acetone, Toluene, Methanol, Methyl Chloride, Dimethy Formide, Dimethyl Sulfoxide, Dioxane, Hydrofluoric acid (other than momentary exposure during probe tip cleaning or momentary sampling)

Avoid static electricity or other electrical charges. The sensor can be damaged by electrostatic discharge or charged electroplating baths.

Avoid applications where the product to be measured is too viscous as to provide good contact with the sensor surface. The sensor is slightly recessed to prevent damage. If the sample is very thick it may be difficult to obtain good contact with the sensor. Results may then be erratic.

After use in meats, foods, fats, oils, blood, human or animal serum, or other compounds containing proteins, grease or oils, always clean the probe well with a toothbrush and mild detergent. Rinse the probe well with deionized water. Store the probe dry with the protective cap covering the probe tip.