What Are the Differences Between Direct-reading Remote-transmission Water Meters and Removable Element Woltman-type Water Meters?

Direct-reading remote-transmission water meters and removable element Woltman-type water meters differ in application scenarios, functional characteristics, technical parameters, and other aspects. Direct-reading remote-transmission water meters are suitable for water consumption measurement in civil buildings, with an emphasis on data remote transmission and intelligent meter reading management; while removable element Woltman-type water meters are mostly used in industrial settings and for large-diameter pipelines, focusing on convenient maintenance and high-precision measurement. ## 1. Differences in Application Scenarios - **Direct-reading remote-transmission water meters**: Mainly used to measure the total amount of drinking cold water in tap water pipelines with unidirectional water flow. They are suitable for scenarios requiring remote meter reading, such as civil buildings and residential communities, to meet the needs of residential water consumption measurement and management. For example, the LXZ-15~40 direct-reading remote-transmission water meters produced by Shanghai Zanke are designed for such scenarios. - **Removable element Woltman-type water meters**: Used to measure the volume of cold (hot) water flowing through pipelines. They can be applied in households and apartments, and are more commonly used in industrial fields and for water flow measurement in large-diameter pipelines. For instance, such water meters are selected for water consumption measurement in some industrial plants. ## 2. Differences in Functional Characteristics - **Direct-reading remote-transmission water meters**: Equipped with remote direct-reading function, they realize long-distance data transmission through M-BUS/RS485 bus communication. Using photoelectric direct-reading technology, they directly determine the position of the water meter's character wheels, ensuring that the mechanical reading is consistent with the electronic reading and eliminating reading errors. They also have functions such as low-power design, through-beam reading technology, and automated meter reading management. For example, some products consume no power in the non-meter-reading state, only require short-term power supply during the meter-reading moment, and ensure accurate reading through optical through-beam. - **Removable element Woltman-type water meters**: Adopt a removable element structure, allowing the counter to be disassembled for inspection and maintenance without removing the water meter from the pipeline. They feature a dry dial, magnetic drive, sensitive operation, and low pressure loss. The vacuum-sealed counter can prevent fogging on the dial and maintain clear readings for a long time. Some products also offer optional functions such as pulse output, RS 485 Modbus, and wired remote transmission. ## 3. Differences in Technical Parameters - **Direct-reading remote-transmission water meters**: Taking the products of Shanghai Zanke as an example, the nominal diameter is generally DN15 - DN40, and the range ratios include R80, R100, R125, R160, etc. Parameters such as overload flow Q? and common flow Q? vary depending on the diameter and range ratio. Within the water temperature range of 0.1℃ to 30℃, the indication error is ±2% in the high flow range (Q?≤Q≤Q?) and ±5% in the low flow range (Q?≤Q<Q?). When the water temperature exceeds 30℃, the maximum allowable error in the high flow range is ±3%, while it remains ±5% in the low flow range. - **Removable element Woltman-type water meters**: They have a wider range of nominal diameters; for example, some products have a diameter range of DN50 - DN600. The accuracy grades include R = 50 and Class B. The maximum allowable error is ±5% in the low flow range (from minimum flow Qmin to分界 flow Qt) and ±2% in the high flow range (from分界 flow Qt to common flow Qs) (for hot water meters, the maximum allowable error in the high flow range is ±3%).