Compared to Keysight, HP or Agilent are more famous. Currently, HP is one of the world's largest producers of computers and printers. However, few people know that in the seventies and eighties of the last century, HP was also the largest manufacturer of instruments and instruments in the United States. With the advent of the golden age of IT, HP gradually focused on the computer and imaging industry, and at the end of the last century, it cut off the huge business, including instrumentation, and established Agilent. In 2014, Agilent was split in two, and the electronics and technology sector became what it is today.
 
In the handheld multimeter industry, Keysight or Agilent are among the few brands that can be compared to Fluke. If Fluke's product positioning is comprehensive and covers more levels, then Keysight is a brand for professional users. Although there is no lifetime warranty, Keysight is as good as Fluke in terms of accuracy and reliability. Keysight's products are expensive, and the basic 1230 series is priced at more than 1,000 yuan. The high-precision, high-count 1240/1250/1270 series is priced between 2800~5000 yuan.
 
The Keysight1252B is the top-of-the-line multimeter against the Fluke289C, with a four-and-a-half-digit 50000 maximum count and an accuracy of 0.025%. In the field of handheld multimeters, the accuracy of 0.025% is already the highest level in the industry. The 1252B is quite comprehensive, with all the current mainstream measurement gears, as well as high-end add-ons such as peak and bar readings.
 
The screen refresh speed has always been a shortcoming of digital multimeters, but the 1252B's screen update speed reaches 7 times per second, compared to the Fluke 87V's 4 times per second. However, it must be said that another feature of a high-end multimeter, "bar reading", is actually more useful than speeding up screen updates. This function indicates the numerical size with a scale bar, which is refreshed 30~60 times per second, and can intuitively reflect the real-time changes in voltage and current.
 
In addition to the previously mentioned features, top-of-the-line multimeters such as the Keysight 1252B and Fluke 289C usually have two functions – data logging and PC connection, which allows the measured data to be recorded and uploaded to a computer for data analysis. But it must be said that the price of multimeters with these two functions is relatively expensive, 1252B and Fluke 289C prices are 4000~5000 yuan, if you don't need this function, other high-precision products will be more cost-effective.
 
Another multimeter under the 1250 series, the 1253B, is even more special, although there is no difference from the 1252B in terms of functionality, the 1253B uses a non-traditional OLED screen. On many electronic products, OLED screens are full of gimmicks, but on multimeters, OLED screens are more direct, with high reading contrast, clear indications, and large viewing angles. However, the 1253B battery life is only about 8 hours, in the same positioning products, the 1252B battery life is 36 hours, the slightly lower accuracy 1521B is 72 hours, and the Fluke 289C is about 100 hours.
 
In addition to the 1250 series, the 1240 series with 11000 counts and the 1270 series with 30000 counts are all good high-precision products. Although the accuracy of the two series is not as good as that of the 1250 series, the ability to resist soil and dust is better. If the 1252B is suitable for some applications where precision is critical, then the 1240 and 1270 are more suitable for daily use. The 1270 series is IP54 rated, while the 1241C and 1242C of the 1240 series reach IP67, which is suitable for users working in complex environments.
 
For users who only need a basic precision multimeter, the 1230 series is also an option. This series of multimeters has 6000 counts and a basic accuracy of 0.5%, which is sufficient most of the time. What's special is that all products under the 1230 series have low impedance steps (LOZ). When measuring voltage, the higher the impedance of the multimeter in general, the better, because the multimeter needs to be connected in parallel with the circuit during the measurement, and the higher the impedance, the less the impact on the circuit. However, in a few cases, the close proximity of the live conductor to the uncharged conductor in the circuit will form a capacitor that will generate a false induced voltage, which can be eliminated by using the low impedance mode. In addition to the 1230 series, some models of Keysight 1240 and 1270 series, and Fluke 117, 289 and other models also have this range.