2016年9月14日星期三

How to Buy a pH Meter

A substance's pH is a measure of its acidity or alkalinity as expressed in the concentration of hydrogen ions it contains. The pH (short for "power of hydrogen") scale is created by multiplying the exponent for the concentration of hydrogen ions in solution (0.1 equal to 10 to the power of -1, 0.01 equal to 10 to the power of -2) by -1. The pH scale runs from 1 to 14; vinegar (acetic acid), has a pH of 2, while a strong alkali like caustic lye (sodium hydroxide) has a pH of 12, and pure water, considered neutral, has a pH of 7. Such things as blood, soil, battery acid, and swimming pools are pH tested, but pH testing is especially important in ensuring the safety and quality of foods ranging from coffee and cheese to beer and wine. Although litmus paper can be used to test acidity in foods with a pH of 4.0 or less, the best way to ensure correct pH is by using an electronic pH meter, which uses a thin, glass-tipped probe to measure voltage changes caused by the hydrogen ions in solution. Here's what to look for when shopping for a pH meter.

1
Look for a sufficient level of accuracy. Meters used to measure pH in scientific research are accurate to within 0.002 pH units. If you're buying a pH meter to test the acidity of food, you'll most likely want a unit with an accuracy of 0.01 to 0.02 units, although you can get by with a pH meter with an accuracy of 0.2 units if the pH of the food item you're making won't exceed 4.0.
For certain foods where the sugar-to-acid ratio is important, such as jellies, jams, and preserves, you'll want a more accurate meter, regardless of the pH of the food, as the pH will affect the temperature at which the food jells and how well it sets. For other flavor-sensitive foods, using a less accurate pH meter could cause you to add acid when you don't need to and so alter the food's flavor.
Using a less accurate pH meter with foods whose pH can exceed 4.0 runs the risk of allowing foods with an unsafely high pH (4.6 or higher) to go on the market.

Your pH meter should not only be accurate, but its results should also be consistent from reading to reading. If it gives widely different results a minute apart, it's not reliable.

2
Look for a pH meter with at least 2-point calibration. To ensure accuracy, the pH meter must be calibrated to ensure its readings are accurate. Calibration is done with standard solutions of known pH. There are 3 standard solutions: pH 4, pH 7, and pH 10. If you are buying a pH meter to test acidic foods, you need to have 2 points of calibration, pH 4 and pH 7. If you are buying a pH meter for scientific research, then you'll also need the pH 10 calibration standard solution.
Calibration solutions are color-coded for easy identification. The pH 4 solution is usually red, the pH 7 solution is usually yellow, and the pH 10 solution is usually blue.

You should calibrate your pH meter at the same temperature as the item you're testing to ensure accuracy.

3
Choose a unit with the appropriate style of electrode for your testing needs. If you're pH-testing foods with little or no oil, or foods where oil can be added later or separated out, you can get by with standard glass-tipped electrodes. For foods with a high-oil content where the oil cannot be separated out, such as salad dressings, you will need electrodes that won't be clogged by the solution they're immersed in.
Some pH meters come with several types of electrodes, while other meters require you to buy the electrode you need separately.

If you are going to use the pH meter in a number of places, choose a meter where the electrode isn't permanently attached. If the electrode breaks, your meter will be useless.

4

Look for a durable unit. Your pH meter should be rugged enough to stand up to the environment or environments you'll be using it in. A unit designed to be taken into the field should be resistant to dirt and possibly also to harsh chemicals. If you test for acidity on just-cooked foods, your pH meter should be able to withstand a temperature of at least 160 degrees Fahrenheit (71 degrees Celsius).

5
Look for automatic temperature compensation. Because pH readings are affected by temperature, buying a pH meter with automatic temperature compensation is helpful if you produce a large amount of food items that need to be tested and don't have the time to let the food cool to room temperature before testing. The temperature compensation feature should have a range that covers the temperature at which your sample is to be tested.

If you use a pH meter without temperature compensation, you can either test samples only at room temperature or use a temperature compensation chart to determine the correct pH.

6

Consider a pH meter that connects to a computer. This kind of meter automatically transfers a sample's pH and temperature readings to the computer, useful if you routinely test a large number of samples at a given time. This feature adds about $75 to $100 to the overall cost of the pH meter, however, so if you test only a small number of samples at a time, you may not be able to justify the additional cost.

7

Shop for the best price. You can buy a pH meter from a scientific supply company or directly from the manufacturer' website. Prices range from under $100 to over $1,000; to get the best deal, assess your needs and ask the company's representatives about the capabilities and features of their pH meters before you buy.

YK Scientific Instrument is a professional manufacturer and supplier of kinds of PH Meters with or without Temperature Compensation.

Any enquiries, please email us: sales@yk-instrument.com


9 Different Types of Spectroscopy Techniques & their Uses

Spectroscopy is that branch of physics which deals with interaction light with materials. In other words it is an analytical method for qualitative and quantitative estimation by use of light.

Light is as we all know is an electromagnetic radiation which has wave and frequency as measurable characters.

You can know more details here on the principle of spectroscopy.

Spectroscopy finds wide spre 0ad application in daily life. It is used in analytical chemistry, phyto-chemistry (plant chemistry), biological analysis, health care and medicine.

Further is became a part of other means of estimation and analysis like in chromatography, elemental analysis and also identification tools.

This is mainly of 3 types which is again classified into subtypes.

THE DIFFERENT TYPES OF SPECTROSCOPY INCLUDE:

a. Based on the level of study. Here the classification is done based on the study made at atomic or molecular level. When light is allowed to pass through the substance, changes in atomic level or molecular level is observed.

1) Atomic spectroscopy: Here energy changes takes place at atomic levels. The measurement is done to study the atoms and their quantity. This is of two types as atomic absorption spectroscopy and atomic emission spectroscopy. These are referred as atomic absorption spectroscopy and flame photometry respectively.

Here the sample mostly metals and their formulations are converted to atomic forms and then measured. Ex: Sodium, calcium, magnesium related formulations.


This finds less application as the characters of most substance are depended on the molecular nature and not just atoms in it.

Also the methods are expensive, time taking and even quite tedious to perform.

2) Molecular spectroscopy: Here the energy changes occurring at the level of molecule are studied. The characters like molecular absorption. emission and vibration are studied.

The examples include, colorimetry, UV-spectroscopy, infra red, FTIR, fluorimetry etc.

This method of spectroscopy is widely used due to many applications. The methods are quick, easy and accurate in determination. Further they are easily integrated into other analytical techniques like chromatography.

B) Based on the property of either absorption or emission.

Here the principle of abortion or emission of electromagnetic radiation is taken into consideration.
1) Absorption spectroscopy: As the name suggests, here there is absorption of light by the sample. The extent of absorption and the wavelength of the absorbed light is considered. The wavelength of light absorbed tells the nature of the compound while the intensity of absorbed light tells the concentration.


The examples of the spectroscopic methods coming under this method are colorimetry, UV-spectroscopy, infra red spectroscopy, Nuclear magnetic resonance (NMR), atomic absorption spectroscopy.

2) Emission spectroscopy: Contrary to the above method, here the emitted light is measured. once the light impinges on the sample, some of it is absorbed. This absorption of light leads to transition of electrons from ground state to excited state. These excited electrons return back to ground state by release of electromagnetic radiation (light) of specific wavelength. The intensity gives the concentration while the wavelength tells the nature of the compound.

Examples include fluorimetry, flame photometry.

C) Based on the level of study i.e. electronic or magnetic levels.

Here the study is done based on electronic or magnetic properties of the compound. Light is an electromagnetic radiation. That is it has both electronic and magnetic properties.

Electronic spectroscopy: So when a compound is estimated without the magnetic field we call it electronic spectroscopy. In this method the substance under test is exposed to light without the influence of magnetic field.

Examples of this method are again colorimetry, UV-spectroscopy, IR, fluorimetry etc.

Magnetic spectroscopy: Here the substance is exposed to electromagnetic radiation in presence of external magnetic field.


Examples include Nuclear magnetic resonance spectroscopy (NMR), Electron spin resonance spectroscopy (ESR).

Any enquiries, please email us: sales@yk-instrument.com

2016年9月13日星期二

New UV-Vis spectrophotometer simplifies sample quality decisions

Life scientists who work with DNA, RNA and proteins can make educated decisions about sample suitability in experiments using a standalone, microvolume spectrophotometer for accurate quantitation and purity measurements to ensure downstream application success.

The Thermo Scientific NanoDrop One and NanoDrop OneC UV-Vis microvolume spectrophotometers are designed to help life science researchers gain a more complete understanding of sample quality and avoid costly delays due to troubleshooting and repeating experiments. These new spectrophotometers introduce the Thermo Scientific Acclaro Sample Intelligence technology, which enables researchers to:

Identify sample contaminants and obtain corrected concentration results;
Receive instant feedback about sample quality with on-demand technical support and guided troubleshooting; and
Confidently measure samples with embedded sensor and digital image analysis.
“Building on the success of previous NanoDrop instruments, used by thousands of scientists worldwide, we have designed the NanoDrop One instrument to provide simplicity and speed as well as information on sample quality. This allows scientists to accurately quantify and qualify nucleic acid and protein samples, so they can  make informed decisions on sample use in downstream applications,” said Dr. Voula Kodoyianni, product manager, molecular spectroscopy, Thermo Fisher Scientific.

The NanoDrop One instrument with its high-resolution, touchscreen interface makes it simple to use as a compact, ergonomic instrument, while the powerful auto-range pathlength technology facilitates accurate measurements for concentrated samples with no need for dilutions.

The patented NanoDrop sample-retention system measures 1-2 µL of sample in seconds without the need for cuvettes, making it a cost- and time-effective solution for busy labs. Workflows can be streamlined on the NanoDrop One instrument with the Auto-Measure functionality, while modern connectivity allows results to be shared and archived via Wi-Fi, Ethernet or USB. The NanoDrop OneC instrument contains both pedestal and cuvette measuring positions, increasing dynamic range and assay flexibility.

YK Scientific Instrument is a professional supplier of UV-Vis spectrophotometer.
Any enquiries, please email us: sales@yk-instrument.com

How to select a laboratory balance?

1. Weight Capacity of the Analytical Weighing Balance

You’ll need to select a balance that displays sample weight to the resolution desired. This is described as readout. Readout can be to several decimal places presented in grams or milligrams.

Select a balance with a weighing capacity in excess of the samples you plan to weigh. Some balances also specify the minimum load that can be placed on the weighing plate.

2. Analaytical Balance Weighing Errors

Balance errors are expressed several ways including: linearity and repeatability. Linearity describes the maximum difference between the true weight of the sample over its weighing range and the deviation of readout from that weight.   If you draw a plot of the real sample weight vs. the weight displayed, for a perfect balance this plot would be a straight line.  But nothing is perfect. Laboratory balance specification tables present linearity as a plus/minus (±) figure which represents the maximum ± deviation of the curve from the straight line. For ABT balances with a 10 mg minimum sample size linearity is ±0.2 mg or ±0.3 mg depending on balance capacity; for the ABT balance with a 1 mg minimum load and 101 g capacity linearity is ±0.15 mg.

Repeatability (designated by some manufacturers as reproducibility) is the ability of a balance to display the same result when an object is repeatedly weighed under the same conditions.  Repeatability is usually the standard deviation of 10 consecutive measurements of a calibrated test weight. In the 10 mg minimum load balances discussed here repeatability is 0.1 mg, and for the 1 mg minimum load balance it is 0.05 mg.

Analytical balance accuracy is highly dependent on where the instrument is placed and how it is maintained.  We direct your attention to our post on setting up and maintaining your balance to avoid weighing errors and to insure long term reliable performance.  Again we invite you to contact our experts for advice and suggestions on choosing the correct balance for your weighing requirements.

YK Scientific Instrument is a professional manufacturer and exporter of Laboratory Balances.

Should you have any enquiry, please contact us: sales@yk-instrument.com

2016年7月19日星期二

High Performance Electrochemical Measuring Instrument PH & Conductivity Testing Meter

PH & Conductivity Meter with Touch Screen




The PH Meter can be widely used for monitoring of Hydroponic, Aquarium, Swimming Pool, Spa,  Wine, Sewage, Urine,  Paddy Feilds

Features:

1. High resolution 7" color screen
2.Three optional resolution: 0.1/0.01/0.001
3. New users can be created with a unique ID, which will be saved to library together with the testing results. So it is convinient for different users' operation.
4. Max 200 sets test results can be saved, which can be transfered by USB port.
5. Three standard optional: Europe, America and China.

Technical Parameters:

1. Measurement Range: 
PH: -1.999-19.999
Temp: -10-110 Celsius Degree
MV: -1999.9mV ~ 0 ~ 1999.9mV 
Conductivity: (0.00~20.00)μS/cm 
(0.0~200.0)μS/cm
(200~2000)μS/cm 
(2.00~20.00)mS/cm
(20.0~200.0)mS/cm
(200~2000)mS/cm (K=10)
TDS: (0 - 100)g/L 
Salinity: (0-100)ppt

2. Resolution: 
PH: 0.1/0.01/0.001
Temp: 0.1 Celsius Degree
MV: 0.1mV ±0.03% FS

Conductivity: 0.01/0.1/1μS/cm; 0.01/0.1/1 mS/cm

3. Net weight: 880g
4. Dimension: 160*190*70mm

To know more information, please contact via email: sales@yk-instrument.com

Water Quality Testing PH Tester with Touch Screen(Measurment Range: -2.00 - 19.99)

PH Meter with Touch Screen



The PH Meter can be widely used for monitoring of Hydroponic, Aquarium, Swimming Pool, Spa,  Wine, Sewage, Urine,  Paddy Feilds

Features:

1. High resolution 7" color screen
2.Three optional resolution: 0.1/0.01
3. New users can be created with a unique ID, which will be saved to library together with the testing results. So it is convinient for different users' operation.
4. Max 200 sets test results can be saved, which can be transfered by USB port.
5.Three standard optional: Europe, America and China.

Technical Parameters:

1. Measurement Range: 
PH: -2.00-19.99
Temp: -10-110 Celsius Degree
MV: -1999.9mV ~ 0 ~ 1999.9mV 

2. Resolution: 
PH: 0.1/0.01/0.001
Temp: 0.1 Celsius Degree
MV: 0.1mV ±0.1% FS

3. Net weight: 880g
4. Dimension: 160*190*70mm

To know more information, please contact via email: sales@yk-instrument.com



Electrochemical Instrument PH Meter with Touch Screen (PH Measurement Range: -1.999 - 19.999) Hydroponic Aquarium Swimming Pool Spa

PH Meter with Touch Screen



The PH Meter can be widely used for monitoring of Hydroponic, Aquarium, Swimming Pool, Spa,  Wine, Sewage, Urine,  Paddy Feilds

Features:

1. High resolution 7" color screen
2.Three optional resolution: 0.1/0.01/0.001
3. New users can be created with a unique ID, which will be saved to library together with the testing results. So it is convinient for different users' operation.
4. Max 200 sets test results can be saved, which can be transfered by USB port.
5. Three standard optional: Europe, America and China.

Technical Parameters:

1. Measurement Range: 
PH: -1.999-19.999
Temp: -10-110 Celsius Degree
MV: -1999.9mV ~ 0 ~ 1999.9mV 

2. Resolution: 
PH: 0.1/0.01/0.001
Temp: 0.1 Celsius Degree
MV: 0.1mV ±0.03% FS

3. Net weight: 880g
4. Dimension: 160*190*70mm

To know more information, please contact via email: sales@yk-instrument.com


2016年6月22日星期三

How to operate Mini Magnetic Stirrer

R100 Intelligent Magnetic Stirrer with Timing Function

1. Product Features

1)Intelligent chip design, 5 speeds adjustable, 2 kinds of stirring mode, timing function.
2)ABS house, small footprint, anti-slip foot pads ensure stirring stability.

3)IP54 dustproof and splashproof.

4)LED display screen.

5)Optional electrode holder.


2. Technical Parameter:

1)Speed range:5 gears (500rpm to 2500rpm)

2)Working diameter: 110mm

3)Max. stirring capacity: 5000ml

4)Power: DC12V

5)Dimention: 160 x 120 x 65mm

6)Weight: 590g


3. Operation of Magnetic Stirrer

1) Remove black waterproof rubber cap, plug in adapter. 
2) Place the vessel with medium on work pan, put a stir bar into vessel. Please note that the vessel should be placed on the center of work pan.
3) Press “on/off” button, indicator light in red color.
4) 
Press “ Mode/▵” button to select Counter-clockwise and Clockwise mode or Clockwise mode.
5) Press “ Rev/▿” press to select speed (Totally five speeds). 
6) Press “ Start/Stop” button to start or stop operation.  
B. When the medium was mixed well, press Start/Stop button again, the stirrer will stop working, the indicator light turns red.

















A. After choosing stir direction and speed, we can press Start/Stop button to have the stirrer start working, the indicator light turns green from red.





7Press “Timing” to set timerTimer Range: 30s-99 Minutes 99s.

Press "TIMING", "10:00" is flashing and a clock icon on the screen,this means
timer is 10 minutes. If you want timer above 10 minutes, press "MODEL/▵" shortly can increase 1s each time, and press "MODEL/▵" long time can increase 10s each time;
If timer exceed the time you need, press "REV/▿" shortly can decrease 1s each time, and press "REV/▿" for long time can decrease 10s each time.

Press "TIMING" again, quit timer setting.

There are 2 functions of timing:

A. When the stirrer is not working ( indicator light in red), it will start to stir when time is up.

B. When the stirrer is working ( indicator light in green), it will stop stirring when time is up.

2016年1月12日星期二

Halogen Moisture Balance Moisture Analyzer for Grain Seed Food Paper


Halogen Moisture Balance Moisture Analyzer for Grain Seed Food Paper 

Features

1. LCD Display
2. Touch-tone chain plate makes the operation easier.
3. The high precision heat insulation sensor makes temperature for data acquisition reliable.
4. The use of halogen lamp for heating, makes test time shorter.
5. In the process of test, the dry state can be directly confirmed to speculate the finish time.
6. It is equipped with automatic tare function, it can measure immediately and continuously.
7. RS232 interface, the products can be directly connected to computer and printers.

8. Applications: chemical raw materials, grain, mineral, biological product, food, pharmaceutical raw materials, paper, textile raw materials and etc.
9. Two Weighing Pans supplied as standard.

Technical Parameters

Weighing Capacity: 10g
Readability: 10mg
Repeatability: 0.5%
Heating Temperature Range: 50-180 Celsius Degree
Heat Time: 1-99min, 1 min interval

YK Scientific Instrument is a professional supplier and exporter of Moisture Balance. 

For more information, please feel free to contact us via email: 
sales@yk-instrument.com

2016年1月3日星期日

Compact Magnetic Mini Stirrer Without Heating (Work Platform Dia 100mm )



Compact Magnetic Mini Stirrer Without Heating

Magnetic stirrers are ideal laboratory instruments for PH-Metering, extraction and dialysing with the small quantities of substances.

1. Compact Design
2. Space-saving Design
3. Ideal for titration applications
4. Max Speed: 2500rpm
5. Precise speed control
6. Only a small amount of heat on continuous running
7. Body: Polypropylene

Features

1. Compact and space saving design for narrow area.
2. Ideal for titration applications and small vessels.
3. Almost no heat-up of the plate.
4. Smooth acceleration of stirring speed ensures no spillage.
5. Easy to assembly and disassembly support rod with the clamp on rear side.
6. The stirrers are supplied with two cylinder-shape manetic stiring bars encapsulated in PTFE for universal use.



For more informations, please contact us via email: sales@yk-instrument.com

YK Scientific Instrument Co.,Ltd