The role of "Cumulative Flow" data in flow monitoring.

Outline of this Article

● What is “Totalizer”?

● The three common monitoring indicators of flowmeters

● How do users obtain the data of "Totalizer"?

● Communication Transmission Recommendations

● Data application of "Cumulative flow"?



What is “Totalizer”?


In general, "Totalizer" is used to count the total amount of material (such as fluid) flowing.


In our daily life, we encounter the application of "Totalizer" to some extent. For example, when we go to the gas station to refuel, "Totalizer" will be the key to payment. The we pick up the fuel gun and flip the switch up, the fuel gauge will reset to zero; after refueling, we hang up the fuel gun and pull the switch back down, the fuel gauge will show how many gallons of gasoline we have refueled the payment will be billed based on this amount of gallons . "How many gallons are refueled" is the so-called "Totalizer". In this scenario, speed is less important, and the "total amount" has a more direct relationship with us. In addition, the water meters, gas meters, and electricity meters that you read every month are also Totalizers, which use the same method to calculate the amount charged.

totalizer's daily life example-gas station refueling

"Totalizer" in the flowmeter refers to the function of accumulating flow. Cumulative flow can be used to control the flow of liquid medicine, waste water, raw food materials, etc. that is transported along specific pipelines, so as to do cost control; precise liquid dosage can also control processing chemical reactions; ensuring the consistency of manufacturing formulations for food, pharmaceuticals, etc. In addition, some electronic flow meters on the market also have the function of accessing the accumulated flow data within a certain period of time.


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The three common monitoring indicators of flowmeters:


➤ Cumulative flow:

The unit of time is fixed, and the volume of fluid flowing through each unit of time. For example, if 50 liters of wastewater is discharged per minute, the instantaneous flow is 50 L/min. Another is, if the wastewater is discharged at an instantaneous flow rate of 50 L/min, assuming that the flow rate does not change at all, and the discharge time is stable for eight hours a day, the cumulative waste water discharge can be 24,000 liters per day.


➤ Instantaneous flow:

LPM is an abbreviation of liters per minute, measured at a certain point in time (such as microseconds or milliseconds). However, this data is only applicable if the instantaneous flow rate is maintained for one minute and also under the condition of constant pipe diameter. In fact, the instantaneous flow rate can be high or low within a period of time, and after a period of time, the measured cumulative flow rate will not be consistent with the instantaneous flow rate. Therefore, the number of instantaneous flow rates does not actually affect the cumulative flow rate in the end. For example: In a period of flow monitoring within ten minutes, the instantaneous flow measured in one millisecond is 60 LPM, and the instantaneous flow in another millisecond is 40 LPM, but after ten minutes, the cumulative flow is 50 LPM.


➤ Flow rate:

The velocity of the fluid flowing through a section per unit time is called the flow rate, which is usually used to monitor the physical quantity of liquid or gas flow changes.


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How do users obtain the data of "Totalizer"?


➤ Manual recording, it is easier to use the 14-day recording function.

On-site personnel monitor and record the cumulative flow back and forth at the installation location of the flowmeter at a certain time and frequency. If the installation location of the flowmeter is far away, time and management costs will increase. LORRIC Paddle wheel flow meter provides 14-day cumulative flow memory, so the personnel do not need to travel frequently every day, which can greatly reduce management and time costs.


➤ LORRIC AxleSense Paddle wheel flow meter with "Daily Accumulation of positive/negative/net flow volume in the past 14 days. "

In the infrastructure of non-process facilities, there is generally no PLC to monitor the system. The LORRIC AxleSense Paddle wheel flowmeter provides the following flow monitoring data accumulation: positive/negative/net flow volume, you can set one of them as Historical data for the past 14 days (data can display up to 10 digits). At the same time, because it is equipped with a backup battery, even if the device is temporarily powered off, the data can be kept intact.


Greatly improved user interface, LORRIC paddlewheel flowmeter that is made convenient for human's beter visibility.


➤ Transmission of data by electronic signal

The manual data recording method does not require external equipment or a central vacant system in the workplace. This method has relative immediacy and reliability (but if you need to calculate more complex application scenarios, you can also use an external recorder to assist).However, due to factors such as cost, size, and design of the screen of the common flowmeter in the market, if the flowmeter is installed in a location where it is difficult to monitor, or under conditions such as dim lighting, it will make the field personnel's visual monitoring very difficult.In relatively large and advanced operating fields, the data of all equipment are coordinated and recorded by external devices, such as PLC (Programmable Logic Controller), generally using RS485, 4-20mA, or switching signals The signal transmission method uses wired communication to connect individual devices and PLCs.This method will have special requirements on the wired communication equipment of individual devices. The above three items are explained as follows:


Switch Signals | The easiest way is to use the built-in alarms that can be set high and low to monitor whether the cumulative flow exceeds the upper limit.

Whether the instantaneous flow is normal can be obtained through "The data exceeds the upper limit of the analog output current" and "The data is less than the lower limit corresponding to the analog output current" built in the flowmeter or in the central control system alarm setting function, but the data cannot be obtained. For example, if the user wants to set the instantaneous flow rate of a fluid on the production line to 60 l/s in order to control the injection speed and volume of the fluid, the user can set the upper limit to 62/lower limit to 61 in the upper and lower limit functions, and the alarm will be generated to confirm whether the fluid flow rate is exceeded or insufficient. When the fluid flow rate is exceeded or insufficient, it will generate the alarm to confirm whether the fluid flow is at a normal value and properly control the amount and speed of fluid injection. Some mechanical flowmeters, such as area flowmeters equipped with a magnetic indicator or a magnetic ring, can transmit the switch signal by setting the upper and lower limits, and confirm the current flow monitoring status. If you want to get real-time cumulative flow data through the switch signal, you can change the switch signal to pulse output, and connect the PLC or counter to get the real-time cumulative flow.


4-20mA|The transmission line is one-to-many, and the delay time for data collection is long, but the data is the most diverse and can be transmitted over long distances.

The RS485 transmission line is a one-to-many connection. If the user does not have immediate needs, RS485 can directly collect various data on the cumulative flowmeter for subsequent applications, which is suitable for data collection. But the PLC engineer needs to write another program to decode the communication content according to the manual of different flowmeters.


RS485|A single dedicated line is generally used to receive instantaneous flow data. In LORRIC paddle wheel flowmeter, it can also be set to output cumulative flow data. Due to the use of a dedicated line, the data is the most reliable and fast, and has the least delay, which is suitable for automatic control applications that require high response time.

For example, when the user is engaged in automatic control, sometimes it is necessary to ensure that the delay requirement is one thousandth of a second or lower, and it is very suitable to transmit data with 4-20mA. However, because the principle is within the current range of 4-20mA, the data will change accordingly according to the flow rate and the preset range, so the correct setting of the corresponding flow range of 4-20mA is the premise of the correctness of the data. If the output value reaches 20mA, manual reset is required to start collecting data again, so there are fewer users using this method. Even so, this method can still be used as a signal feedback for the accumulated flow.


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Communication Transmission Recommendations


Switch Signals 4-20mA RS485 Paper records

Instantaneous Flow

Upper and lower limits can be set, but relatively less accurate, less real-time, and more computationally intensive.


Lower delay for one-to-one dedicated lines.

Relatively long delay. Handwritten record.

Cumulative Flow


The most common is Pulse, which instantly returns the unit volume.

Less used.

Available in LORRIC flow meters, but less commonly used on the market.

The delay is relatively long, and there is a zero-return function.

There is a cumulative flow of dates provided.

Handwritten record. LORRIC provides a 14-day cumulative flow record.


Some Alarms can output via Pulse, but they are limited because it can only select one output (or a large class of output). Less used.


You can get the most information, self-health, settings, environmental parameters.

One wiring can communicate with multiple units.

Handwritten record.


* 🏆 Indicates a more common usage than others.

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Data application of "Cumulative flow"?


We try to use "cumulative mileage" as an analogy to "cumulative flow". "Accumulated mileage" provides the driver's perception of the total mileage the car has traveled since it started Usually, considering the driving safety and prolonging the service life of the vehicle, entering the factory for maintenance within the recommended mileage of the car manufacturer will ensure that the safety of the vehicle itself is not compromised, and the vehicle will always be as new, maintaining its performance and appearance.


"Cumulative flow" has different interpretations in different industries and different applications. For example, in the food industry, the ratio of mixed raw materials will be the key to determining the taste of a certain food. At this time, monitoring the instantaneous flow, the cumulative flow data of individual raw materials will allow the overall raw material mixing ratio to be finely adjusted and controlled to achieve standardized finished products for food manufacturing. In addition, in the use of equipment, the cumulative flow can also become one of the benchmarks for regular equipment maintenance. Generally speaking, the equipment will have suggestions for maintenance time and usage. Accurate cumulative flow records can assist on-site personnel in production lines, planning of operation and regular maintenance schedules.


In addition, in LORRIC's point of view, whether it is "instantaneous flow" or "cumulative flow", both are the basic data that the flowmeter can provide, and are also the so-called environmental data. And any application or process that needs to consider environmental factors, both of these figures will be also important.


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