What is Cumulative flow? Flow 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" 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.

1 ) 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.

2 ) 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.

3 ) 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.

1 ) 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.


2 ) 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.
⇒FP-AS510 Patent AxleSense Paddlewheel Flow Meter
 
3 ) Data Transmission via Electronic Signals
Manual data recording methods do not require additional equipment or a central control system, offering real-time reliability (though external loggers can be used for more complex calculations). However, typical flow meter screens may be challenging to monitor due to cost, size, design considerations, or difficult-to-reach installation points and poor lighting conditions, presenting operational challenges for on-site staff.

In larger and more sophisticated operational environments, data from all devices are coordinated and recorded by external devices such as Programmable Logic Controllers (PLCs). Typically, wired communication methods like RS485, 4-20mA, or switch signals are used to connect individual devices with the PLC. This setup demands specific communication equipment for each device.

1 ) 4-20mA
Commonly used for instantaneous flow data, LORRIC's paddlewheel flow meters can also be set to output cumulative flow data. The use of a dedicated line ensures reliable, fast data with minimal delay, suitable for automated control applications requiring quick response times.
For example, in automated control, where delay requirements might be as low as one thousandth of a second, 4-20mA transmission is ideal. However, data accuracy depends on correctly setting the 4-20mA range according to flow size and pre-set ranges. If the output reaches 20mA, it must be manually reset to continue data collection, resulting in fewer users for this method. Nonetheless, it serves as feedback for cumulative flow signals.
⇒ Learn more: What is Analog Output

2 ) RS485
This one-to-many transmission line has longer data collection delays but offers the most diverse information and long-distance transmission.
The RS485, being a one-to-many connection, is suitable for data collection without immediate timing needs. It can directly gather various data from cumulative flow meters for subsequent applications. PLC engineers must write additional programs to decode communication content according to the flow meter's manual.
⇒ Learn more: What is RS485?

3 ) Switch Signal
The simplest method utilizes built-in settings for upper and lower limit alarms to monitor whether the cumulative amount exceeds limits.
By setting "data greater than the corresponding upper limit of analog output current" and "data less than the corresponding lower limit," one can monitor whether the "instantaneous flow rate" is within normal parameters but cannot capture the data itself. For instance, if users want to control the injection speed and amount of a certain chemical with an instantaneous flow rate of 60l/s, they can set the upper limit to 62 and the lower limit to 61. Alerts for exceeding or falling short help ensure the chemical flow rate is controlled correctly. Mechanical flow meters with magnetic pointers or rings can transmit switch signals based solely on these limit settings, confirming the current flow monitoring status. For real-time cumulative flow data through switch signals, changing the output to a pulse signal and connecting to a PLC or counter can provide immediate results.
⇒ Learn more : Switch Signal

Comparing 'cumulative flow' to 'cumulative mileage,' which informs a driver of the total distance a vehicle has traveled since its inception. Regular maintenance within the manufacturer's recommended mileage ensures vehicle safety and longevity.

'Cumulative flow' varies in interpretation across industries and applications. For example, in the food industry, the proportion of mixed ingredients is crucial to the taste of certain products. Besides monitoring instantaneous flow, the cumulative flow data of individual ingredients allows for precise adjustments and control, leading to standardized food production. Additionally, cumulative flow can guide regular maintenance schedules for equipment, with precise records aiding operational and maintenance planning.

LORRIC views both 'instantaneous flow' and 'cumulative flow' as fundamental data provided by flow meters, important for any application or process where environmental factors are considered.