Portable Colorimeter, D/8 Structure,8mm Caliber,Universal Colorimeters for Various Industries,Massive Storage of Data,Supporting APP and Computer Software

Doing some research in advance, I found the manufacturer and was able to find and side load the APK for the app. Advance scanning showed the app to be safe, at least in its initial state. I don't make a habit of sideloading Android apps, and I strongly encourage the manufacturer to get their act together and get this thing approved by the Google Play store. Period.First things first, once the app is installed, you need to charge it a bit more. It arrived at roughly 50 or 60% of full charge, but I tested the charge and wanted to be sure the battery was topped up. Unexpectedly, this is the MAX of this meter, which is the top model made by this manufacturer in their compact cylindrical size range. It has higher accuracy than the others and longer battery life. It is claimed to be good for 10,000 measurements. Bear in mind that every measurement flashes a light source internally onto the specimen being measured. Obviously, this reviewer is not going to test 10,000 measurements to see if the battery holds up! The charge receptacle is USB Type-C, and a USB type A to type C cable is included. Initially, it was plugged into a Type-C used for charging my phone, which is a PD (Power Delivery) multi voltage type C to type C charge connection. The colorimeter would not accept a charge. When using a standard 5 volt supply, however, The light on the front, under the display, turned green and charging commenced. All is good.Of note, I have purchased high-end $5,000 to 10,000 spectrophotometers and colorimiters for my engineering laboratories. This is not quite at that level of sophistication, but is surprisingly repeatable.In my application, it is being used for measuring the colors of various 3D printing filaments. It is quite frustrating to purchase a filament, hoping that it is the right color and matches the hex code of the filament you already have. And frankly, some of the published hex codes are not very accurate. That's a whole other problem.The app is incredibly intricate and while, in this reviewer's case, English was selected as the language, there are portions of the app, specifically the library of colors, such as Pantone, RAL, PPG, etc, where the collections are partially in English and partially in Chinese. This premium model has access to the full library of collections for color matching a sample to the nearest Pantone or RAL color, for instance.There are dozens of different light sources, as well as dozens of different color spaces that can be selected for use. I selected d65, which is the most common illuminant and is typically used for representing daylight. F2 is also one of the many options and typically is used to represent fluorescent lights. There are dozens more, and it's a big confusing to determine which one to use. I truly have no idea what the manufacturers are using when they spec a hex code color for their filament. I selected the CIE LAB color space, as again that is quite common in use and happens to be the default set in this device.None of the measured values of my printed sample swatches matched the published color numbers precisely. Nor would one expect that to be the case. The device is extremely good at determining small differences between very similar materials, and providing Delta e and Delta l values if you use this as an inspection product. Poor, if you just want to see how close something is to your target.Color measurement can be initiated by pressing the button on top of the device, or by tapping from the app. It's quite convenient.Initial calibration was a little confusing, as the app asks for black to be calibrated first and having the measurement end pointed at the ground. I did not realize that there was a calibration cap on the end of the device, which is magnetically attached. That needs to be removed when calibrating for black. To calibrate for black, the device is simply held in the air pointed at the ground with the cap off. To calibrate for white the cap is magnetically reattached to the bottom of the unit with the white dot in the cap facing up. The white dot is the reference white color that the device needs to establish colors.The cap also serves as a protective cover.Cons - besides the complexity of the app, with not a whole lot of guidance in terms of how to use it for light source, angle, or color space selection, the user manual comes under a bit of fire. It's printed crisply on glossy white paper. That's great. What's awful is the size of the paper and print. It is simply impossible, even with young eyes, to be able to read this thing. I would prefer that, if a larger page cannot be supplied, that a link to a PDF be provided so that a much larger copy can be printed out and read with ease.In all honesty, despite the complexity of the app, the app having to be sideloaded, and tiny print of the instruction manual, this is an impressive product for the sub $100 price. This reviewer is torn between a four-star and five-star rating but will give it five stars for the amazing value it provides for this level of precision and library of colors that are available.