Refractometers measuring instrument for measuring the refractive index of a substance. There are four main types of refractometers: traditional handheld refractometers, digital handheld refractometers, laboratory or Abbe refractometers, and inline process refractometers. There is also the Rayleigh Refractometer used (typically) for measuring the refractive indices of gases.
In veterinary medicine, a refractometer is used to measure the total plasma protein in a blood sample and urine specific gravity.
In gemmology, a refractometer is used to help identify gem materials by measuring their refractive index.
In marine aquarium keeping, a refractometer is used to measure the salinity and specific gravity of the water. In basic terms, gloss is a facet of visual perception in various objects and surfaces. The interaction of light with the physical characteristics of a surface is what creates gloss. Materials that are smooth and shiny appear to be very glossy, while rough objects appear to have little to no gloss at all. In basic terms, gloss is a facet of visual perception in various objects and surfaces. The interaction of light with the physical characteristics of a surface is what creates gloss. Materials that are smooth and shiny appear to be very glossy, while rough objects appear to have little to no gloss at all.
What a gloss meter does is measure the light that is reflected by a light source at a specific angle, called a specular reflection. In simple terms, you shine a specific amount of light onto a surface and measure the reflection that is being generated. Now, when measuring gloss, you can’t just shine any old light in any old way onto a surface. It is a very exact and specific science to properly measure gloss.
A gloss meter measures specular reflection. The light intensity is registered over a small range of the reflection angle. The intensity is dependent on the material and the angle of illumination. In case of non-metals (coatings, plastics) the amount of reflected light increases with the increase of the illumination angle. The remaining illuminated light penetrates the material and is absorbed or diffusely scattered dependent on the color. Metals have a much higher reflection and are less angle dependent than non-metals Color difference Meter.
A glossmeter gives the amount of reflected light from a sample, compared to that reflected from a black glass calibration standard with a defined refractive index. The result is independent of the amount of incident light. The gloss value of the reference standard is defined to be 100 gloss units. Materials with a higher refractive index can have a measurement value above 100 gloss units. For transparent materials, the gloss can be increased by multiple reflections in the bulk of the material. Due to the high reflectivity of metals, values as high as 3500 gloss units can be obtained. For these applications it is common to use percent reflection of incident light rather than gloss units. Use this gloss meter to evaluate the gloss of any coated surface, check paints or inks, inspect print materials, and more! Using an infrared source that emits a beam of light at an angle to the surface, a sensor measures the reflected light.
Features a 3-digit LCD and is switch selectable for a standard 60° measurement angle or a 20° angle for measuring high-gloss surfaces. Sensor is separate from meter for measuring hard-to-reach surfaces. Note: Not recommended for polished metals.
1-ft (30.5 cm) coiled connection cable and four 1.5 V AAA batteries
A tachometer, also known as a tachymeter, is an instrument on many sophisticated watches that lets you determine the speed at which you, or another person or object, are traveling. If your watch has a tachometer, it will have a ring of numbers encircling the outside of its face, usually running from 500 to 60. It will also have a chronograph, or stopwatch, function, since you need this feature to use the tachometer. Tachometers are only present on analog watches . Press the “mode” button on your watch until you are in chronograph mode. At this point, the second hand on your watch should stop moving when it reaches 12 o’clock. · Pick a point spatially ahead of you where you would like to start your speed measurement. For your first practice, use a mile marker while driving. As you pass this marker, push the set button to start the chronograph. The second hand will proceed clockwise around the face. Press the set button again when you have traveled one mile. At this point you will pass a second mile marker.
Look at the second hand of your watch. Determine what number position it is pointing to on the tachometer dial. This number represents the speed at which you were traveling in miles per hour. For example, if you took a minute to drive the mile, it will point to 60, meaning you drove at a speed of 60 miles per hour.
Measure things that move slower than 60 miles per hour by taking the tachometer’s reading and dividing it. For example, there is no way a runner can travel one mile in a minute. Instead, record the amount of time it takes him to go a preset fraction of a mile. For example, measure one eighth of a mile, then divide the result on the tachometer (say, 60, if he completed the mile in one minute) by eight. You will get the result that he runs a 7.5-minute mile.
Do the same for objects that are too fast for the tachometer, except multiply your results instead of dividing them. The smallest increment it can record traditionally is 7.5 seconds
Coating Thickness Gauges is an important variable that plays a role in product quality, process control, and cost control. Measurement of film thickness can be done with many different instruments. Understanding the equipment that is available for film thickness measurement and how to use it is useful to every coating operation.
The issues that determine what method is best for a given coating measurement include the type of coating, the substrate material, the thickness range of the coating, the size and shape of the part, and the cost of the equipment. Commonly used measuring techniques for cured organic films include nondestructive dry film methods such as magnetic, eddy current, ultrasonic, or micrometer measurement and also destructive dry film methods such as cross-sectioning or gravimetric (mass) measurement. Methods are also available for powder and liquid coatings to measure the film before it is cured. Micrometers are sometimes used to check coating thickness. They have the advantage of measuring any coating/substrate combination but the disadvantage of requiring access to the bare substrate. The requirement to touch both the surface of the coating and the underside of the substrate can be limiting and they are often not sensitive enough to measure thin coatings. Two measurements Ultrasonic Thickness Gauges must be taken: one with the coating in place and the other without. The difference between the two readings, the height variation, is taken to be the coating thickness. On rough surfaces, micrometers measure coating thickness above the highest peak
Instructions on use
- The Vernier caliper is an extremely precise measuring instrument; the reading error is 1/20 mm = 0.05 mm.
- Close the jaws lightly on the object to be measured.
- If you are measuring something with a round cross section, make sure that the axis of the object is perpendicular to the caliper. This is necessary to ensure that you are measuring the full diameter and not merely a chord.
- Ignore the top scale, which is calibrated in inches.
- Use the bottom scale, which is in metric units.
- Notice that there is a fixed scale and a sliding scale.
- The boldface numbers on the fixed scale are centimeters.
- The tick marks on the fixed scale between the boldface numbers are millimeters.
- There are ten tick marks on the sliding scale. The left-most tick mark on the sliding scale will let you read from the fixed scale the number of whole millimeters that the jaws are opened.
The Vernier Caliper is a precision instrument that can be used to measure internal and external distances extremely accurately. The example shown below is a manual caliper. Measurements are interpreted from the scale by the user. This is more difficult than using a digital vernier caliper which has an LCD digital display on which the reading appears. The manual version has both an imperial and metric scale Gauge Blocks .
Manually operated vernier calipers can still be bought and remain popular because they are much cheaper than the digital version. Also, the digital version requires a small battery whereas the manual version does not need any power source.
How does mechanica read micrometer
To learn to read the ROK micrometer you need to understand the Thimble and the Sleeve.
Here we are going to learn to read the micrometer by figuring out the markings on the Thimble and the Sleeve The Sleeve does not move. It looks like a ruler with ten numbers. The space between each number is divided into quarters. As the Thimble rotates around this Sleeve it covers up, or reveals the numbers marked on the Sleeve. It is easy to read a micrometer if you think of the markings on the Sleeve as dollars and quarters
Outside Micrometers give you a chance to read measurements too small for a ruler. To read one, start from the left and work your way to the right. Set the micrometer to zero before you start. If your micrometer doesn’t read zero, check the owner’s manual to learn how to recalibrate it. When you measure something with the micrometer, it should shift from zero to the measurement for the object. For more accurate measurements, use a vernier with the inside micrometer.
Know the parts of the micrometer before you read it. The micrometer is divided into the sleeve and the thimble. Notice that the sleeve’s horizontal position contains numbers 0.1 inch apart, and tick marks 0.025 inches apart. View the numbers on the thimble, which are vertically listed. Count each tick on the thimble as “0.001” inches apart. If you have a vernier ruler on your electronic micrometer, read each tick on that ruler as 0.0001 inches apart. Notice that the vernier is also vertical, and is right next to the numbers on the thimble.
Read from the sleeve of the detpth micrometer to start your measurement. Start with the numbers, then add the tick marks. For example, if you see a “1” and one visible tick mark on the sleeve, read that as 0.1 plus 0.025, or 0.125 inches. Notice how these ticks are perpendicular to a horizontal line that goes to the thimble. Read the tick mark on the sleeve immediately below that line. If that tick mark represents 24, add 0.024 inches to the result you got from the sleeve to get 0.149 inches.
Read a vernier micrometer using the same concept that you use reading the sleeve and the thimble. If your micrometer has a vernier ruler, look for the line of the number that almost perfectly lines up with one of the numbers on the sleeve. Count each of these ticks as 0.0001 inches. Use the example in Step 2, only this time with a vernier ruler. Imagine that number 9 on the vernier ruler is almost perfectly lined up with the tick mark on the sleeve. Since each tick on the vernier ruler is 0.0001 inches apart, read that as 0.0009 inches, and add it to the result from Step 2: 0.149 + 0.0009 = 0.1499 inches.
ROK Torque (tightening force) is critically important when working with any fasteners that will be subject to some kind of load. The bolt (or nut) needs to be “preloaded” with the correct amount of force, so that it will neither break nor come loose and fall off. Automakers specify torque settings for just about all their fasteners, and a torque wrench is used to achieve the requirements.
There are a few different kinds of torque wrench manufacturer out there, from the simple “beam” type that’s available just about everywhere very cheaply, to very sophisticated and specialized ones that measure more than just the bolt’s resistance to movement. It is not the purpose of this article to cover all this; any search engine will lead you to that information. The purpose of this article is to show you what’s inside one of the most common type of torque wrenches used by the automotive repair industry: the click-type torque wrench So, you tighten a bolt with your trusty click-type torque wrench, and eventually you get that satisfying “click” noise when the proper torque has been reached. The “click” is a handy indicator for sure, but what actually makes that click? What’s really going on in there?
A beam–type torque wrench is a tool that is highly susceptible to breakage. dial torque wrench Quite simple in form, this tool consists of a long lever arm that stretches from the handle to the wrench’s head. The torque wrench is made to bend elastically when responding to applied torque. A second bar, used as the indicator, is connected to the head and sits parallel to the lever arm. This bar doesn’t bear any torque and, therefore, stays stationary. The torque wrench has a calibrated scale to measure the amount of applied torque, measured by the bend on the main lever which, in turn, moves the scale under the stationary bar. The most common problems seen in beam–type torque wrenches are related to the pointer beam. This beam may either fall out of calibration or even rest on the scale, hampering the accuracy of the tool. Read on to learn how to repair various problems with your beam-type torque wrench.
Fixing the Calibration
Beam–type torque wrenches, like all other torque wrenches, regularly fall out of calibration. You can re–calibrate the torque wrench using a simple re-calibration technique that follows the principle of deflection. Inspect the pointer when the torque wrench is at rest. If the wrench is out of calibration, the pointer will be either on the right or left of the zero marker
Floating the Scale
At times, the pointer may lie against the surface of the scale. In such cases, the indicator beam does not move as freely as it should.
Using a lever between the two beams is the correct way to fix such problems with your pointer in a beam–type torque wrench. Insert the lever between the two beams and pry them little–by–little. Keep checking the scale and the pointer while doing this, as your beam–type torque wrench returns to perfect calibration.
Bending the pointer, to fix this problem, will not affect the accuracy of the readings on the beam–type torque wrench at all.
Breaking a Torque Wrench
In certain cases, especially when you apply more torque than prescribed by the manufacturer or twist the wrench in the wrong direction, there is a chance that the calibration and accuracy may get affected. In worst case scenarios, the beam–type torque wrench may physically break.
In the latter case, there isn’t anything you can do to repair the torque wrench. Your only option is to replace it with a brand new torque wrench as a broken or mended torque wrench will not have the same strength in structure as a completely healthy piece.
Most beam–type torque wrenches come with a lifetime warranty however that is only in the case of usage within the prescribed limits. The steel does not display signs of fatigue or other damage despite years of usage. Storing the wrench safely and maintaining it regularly ensures easy repair for a broken beam–type torque wrench.
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ROK Digital calipers are extremely economical and accurate measuring instruments. They usually have a resolution of 10 µm with an accuracy of 30 to 40 µm. This high performance and cost efficiency is achieved with the use of multiplate capacitive sensors dial caliper.
Capacitive sensors are extremely rugged and simple to build. They are highly linear and immune to mechanical and electronic noise. However, since they rely on capacitance, they are sensitive to liquids. Any liquid that bridges the capacitive plates increases the capacitance. A drop of oil can increase the capacitance by a factor of 80!
Digital calipers can be bought at prices as low as $15 each. They have an LCD read out and a serial output. Considering their usefulness and low price, I have made this web page that puts together some of the information I collected. Many of this information Dial Test Indicators comes from individuals that have posted on the web. These individuals are driven solely by passion but contribute enormously to the advancement of knowledge. Therefore, I believe that it is also my duty to perpetuate knowledge in a similar manner. The earliest vernier caliper has been found in the wreck near the coast. The ship find dates to the 6th century BC. The wooden piece already featured a fixed and a movable jaw.Although rare finds, caliper remained in use by the Greeks and]
The modern vernier caliper, reading to thousandths of an inch, was invented by American Joseph R. Brown in 1851. His Brown and Sharpe company inaugurated true precision manufacture in the United States. It was the first practical tool for exact measurements that could be sold at a price within the reach of ordinary machinists.
Dial calipers manufacturer are comparatively easy to read, especially when seeking exact center by rocking and observing the needle movement. They can be set to 0 at any point for comparisons. They are usually fairly susceptible to shock damage. They are also very prone to getting dirt in the gears, which can cause accuracy problems. Digital calipers switch easily between centimeter and inch systems.They can be set to 0 easily at any point with full count in either direction, and can take measurements even if the display is completely hidden, either by using a “hold” key, or by zeroing the display and closing the jaws, showing the correct measurement, but negative. They can be mechanically and electronically fragile. Most also require batteries, and do not resist coolant well. They are also only moderately shockproof, and can be vulnerable to dirt.
Calipers may read to a resolution of 0.01 mm or 0.0005″, but accuracy may not be better than about ±0.02 mm or 0.001″ for 150 mm (6″) calipers, and worse for longer ones
Weld gauges are an everyday tool for Certified Weld Inspectors. Gauges are available for checking alignment, checking dimensions before welding, verifying weld dimensions, and for measuring the size of porosity, among other items. They can be devided into HI-LO Welding Gauge
The adjustable fillet weld gauge uses an offset arm that slides at a 45-deg angle to make fillet weld length measurements. You simply adjust the arm until it touches the toe of the vertical leg. The gauge is calibrated to 1/32 in. Four screws hold the offset arm in position for future adjustments.
The gauge also measures weld throat thickness to 1/16 in. by adjusting a pointer in position for future reference. If the weld is concave, more filler material can be added to build the weld throat up to standard Cam Type Weld Gauge. The adjustable fillet weld gauge measures both leg lengths and weld throat fillet weld thickness.
Visual Weld Acceptance Criteria Gauge
This type of gauge is used to determine if fillet welds meet U.S. Nuclear Regulatory Commission (NRC) visual weld acceptance criteria for structural weldments — Fig. 5. It easily and quickly checks the four essential measurements required for compliance with the NRC visual weld acceptance criteria: undercut depth, porosity comparison, amount of porosity per linear inch, and crown height.