Instrument Selection | This One Article Is All You Need for Paperless Recorder Selection!

Commonly available paperless recorders in the market come in several housing dimensions, including 144×144mm (with a 5.6-inch LCD screen), 185×156mm (with a 7-inch LCD screen), 288×288mm (with a 10.4-inch LCD screen), 160×80mm, and 80×160mm. For the 144×144mm and 185×156mm housings, the panel cutout dimensions are 138×138mm. For the 288×288mm mid-to-long chart paperless recorders, the panel cutout dimensions are 282×282mm. For the 160×80mm housing, the panel cutout dimensions are 152×76mm, and for the 80×160mm housing, they are 76×152mm.

1.The selection of the housing size for a paperless recorder is based on a comprehensive consideration of factors such as the instrument panel layout, installation location, number of input channels, and cost.

① When replacing on-site paper recorders, small circular chart recorders, small long-chart automatic balancing recorders, or small electronic potentiometers with a paperless recorder, a 144×144mm housing should be selected to maintain the original panel cutout.

② When replacing medium long-chart automatic balancing recorders or medium circular chart recorders with a paperless recorder, it is best to choose a 288×288mm housing. For this replacement, the original panel cutout of 260×260mm (for an instrument housing of 280×280mm) will require appropriate enlargement.

③ For large circular chart recorders, no suitable paperless recorder is available as a replacement due to the significantly larger cutout size.

④ Generally, paperless recorders with 144×144mm or 185×156mm housings are less expensive than those with a 288×288mm housing, assuming they have the same number of input channels and functionality.

⑤ Except for a few manufacturers whose 144×144mm paperless recorders can accommodate up to 1-48 input channels, most manufacturers offer 144×144mm recorders with only 1-12 input channels. If the total number of required input channels exceeds the maximum supported by a single recorder, it becomes necessary to use two 144×144mm or 288×288mm medium long-chart paperless recorders. In such cases, selecting a model capable of handling 48 input channels may be more cost-effective.

⑥ Medium long-chart paperless recorders typically support a greater maximum number of input channels compared to 144×144mm models.

⑦ The 144×144mm and 185×156mm housings are directly interchangeable. The latter features a larger display screen, providing a more comfortable viewing experience for data, while the price remains the same for both sizes.

2、How to Calculate the Number of Input Channels for a Paperless Recorder

The number of input channels is determined based on the count of external signals connected to the paperless recorder. The maximum number of input signals for a single recorder should be less than or equal to the maximum channel capacity allowed by the device. If this limit is exceeded, additional recorders must be ordered.

① Common input signals include current signals, voltage signals, thermocouples, RTDs, frequency signals, resistance signals, etc. The number of input channels for the paperless recorder is determined by the count of input signals. Special attention should be paid: currently, “universal input” for paperless recorders typically refers to standard current signals, standard voltage signals, thermocouples, and RTD signals. User-customized input signals and frequency input signals generally cannot be freely switched.

② The maximum number of frequency signals allowed for a single paperless recorder varies among manufacturers. Users should carefully review the recorder’s selection documentation during the selection process.

③ When a channel of the paperless recorder is used for flow totalization, the channel count should be calculated as follows: a flow totalization channel not requiring temperature and pressure compensation counts as 1 input signal, while a flow totalization channel requiring temperature and pressure compensation counts as 3 input signals.

3、What Are the Functional Options for Paperless Recorders?

Universal signal input, display, recording, curves, AC220V power supply, Chinese menu, USB interface, and standard device memory are the standard factory configurations of paperless recorders.

Alarms, DC24V loop power, analog transmitter output, communication (referring to RS485 communication and Ethernet communication), PID control function, flow calculation function, frequency signal input, user-specific signal input, user-specific function development, special power supply, configuration with USB drive/SD card, increased device memory, English or other language menu interfaces, etc., all belong to user options. Options are added based on user requirements, incur separate charges, and are not included unless selected. Users should carefully review the details during selection.

4、Software for Paperless Recorders

The software for paperless recorders (single-unit version) is provided free of charge by the manufacturer. The multi-unit version software (allowing one PC to simultaneously view data from several paperless recorders) usually requires purchase by the user.

① After installing the free paperless recorder software on a PC, 1 PC can connect via the recorder’s standard RS232 communication port to view data from 1 recorder.

② After installing the paid multi-unit paperless recorder software on a PC, 1 PC can connect via the recorder’s RS485 communication port to view data from several recorders.

5、Choosing Between Blue-Screen and Color Paperless Recorders

Typically, the basic functions of color and blue-screen paperless recorders from the same manufacturer are the same. The main differences are:

① Color paperless recorders can display several data curves and numerical values on the same screen using different colors.

② Blue-screen paperless recorders only display one color and can show a single curve and its corresponding data on the same screen.

③ The operation methods differ slightly.

④ Blue-screen paperless recorders are generally more affordable.

6、Pricing of Paperless Recorders
Branded products inevitably come with higher quality and higher prices. Extremely low-priced paperless recorders are unlikely to be reliable, as no company or individual would sell a quality product below cost. Due to variations in brand value, production costs across manufacturers, and customer maintenance expenses, it is impractical to list and compare all prices in detail. However, products within the same tier tend to be similarly priced.
The price of a commonly configured paperless recorder is typically calculated as follows:
Total Price = Channel Price + Alarm Function Price + Communication Function Price + DC24V Loop Power Price + Transmitter Output Price + Other Optional Feature Prices
① Channel Price = Base Price for Single-Channel Unit + Unit Price per Additional Channel × (Total Number of Channels – 1)
② Alarm Function Price = Unit Price per Alarm Output × Number of Alarms
③ Among communication functions, RS232, RS485, and Ethernet typically incur charges, with Ethernet communication priced significantly higher than RS485.
④ DC24V Loop Power Price = Unit Price per Loop Power Output × Number of Loop Power Outputs
⑤ Transmitter Output Price = Unit Price per Transmitter Output Channel × Number of Transmitter Outputs

7、How to Choose a Manufacturer and Brand for Paperless Recorders
In China, paperless recorders were first produced by Zhejiang University Supcon (SUPCON), after which other domestic manufacturers began production. Currently, manufacturers, distributors, and OEM suppliers all sell paperless recorders online, which can be overwhelming for users. To make an informed choice, consider the following aspects of a manufacturer:

① Experience and Technological Platform: Generally, brands with a longer market presence, higher technological platforms, better cost-performance ratios, and greater market share tend to be more reputable. After all, quality products require time to prove their reliability.

② Technical Specifications: Evaluate key indicators such as accuracy (most manufacturers offer 0.5%, while a few provide 0.2%), stability, temperature drift, anti-interference performance, electromagnetic compatibility, isolation strength, LCD screen quality (preferably imported), and the quality of electronic components used.

③ Production Process: High-performance electronic products typically adopt integrated chips and modular designs, manufactured using wave soldering or SMT (Surface Mount Technology) processes. Hand-soldering methods cannot achieve the same level of product quality.

④ Design and Aesthetics: The exterior design reflects the manufacturer’s attention to detail. An elegant appearance, a bright and clear display, an intuitive interface, and user-friendly buttons all demonstrate the effort invested in the product’s development.

⑤ Warranty Period: The length of the warranty indirectly reflects the manufacturer’s confidence in their product quality. The reasoning behind this is self-evident.