- Digital Flow Meters
Digital Flow Meters
Your Top Resource for
- Industry Leading Warranties
- Expert, PhD-Level Customer Service
- Free After-Sale Technical Support
learn more ›
What Digital HPLC Flow Meters Do
Digital HPLC flowmeters are used to measure the accuracy of High Performance Liquid Chromatography pumping systems in order to meet FDA and other regulations regarding installation qualification (IQ), operational qualification (OQ) and performance qualification (PQ) of equipment used in the pharmaceutical and biopharmaceutical industries as well as other analytical labs.
The process demands accurate, reproducible column retention time as an analyte (what is being analyzed) is pumped through the HPLC system.
These precision instruments are not to be likened to flow meters used on process lines measuring flow rates in, for example, thousands of gallons per minute but instead in fractions of milliliters per minute.
Why Digital HPLC Flow Meters are Popular
The answer is clear when compared to two alternative methods defined as volumetric using a finely graduated cylinder and gravimetric using a precision analytical scale. In either case a stopwatch is needed along with a technician with excellent eyesight and a high degree of patience.
For volumetric measurement, technicians begin to collect HPLC eluent in the graduated cylinder and simultaneously start the watch. When sufficient volume is collected, the technician simultaneously stops the flow into the cylinder, stops the watch, then calculates and records the flow rate in milliliters per minute.
For gravimetric, the process is similar but measured by weight of eluent captured in a tared container.
These tedious, time consuming but critical process repeats over and over until a standard deviation can be calculated. Moreover, solvent evaporation collected in a graduated cylinder can throw off readings.
How a Digital HPLC Flow Meter Works
Contrast this laborious and error-prone approach with the FlowCal 5000 digital liquid flowmeter offered by Tovatech. Compact, portable and lightweight, it operates on the volumetric method and function by taking repeated and accurate measurements of the time it takes a solvent to pass through a small diameter tube.
The Flow Cal 5000 is positioned at the end of HPLC pump systems being tested to receive and measure solvent as it exits the system. This enables solvent to be collected in a bottle for later disposal. The procedure is simple when compared to manual methods.
Here is a sequence of operation that typically takes less than a minute for each reading:
- When solvent enters the base of the flow meter the meniscus passes an optical sensor that activates a timer.
- When the meniscus reaches a second sensor, the timer stops, a valve opens and the tube drains.
- Readings are displayed on the meter’s four-digit LCD panel and recorded to six-digit printer or computer.
- The process repeats itself.
Measurement accuracy is ±1 percent of the reading over flow rates of 0.05 to 25 mL/minute. Consistent readings mean the HPLC pump system is operating correctly. Otherwise the system requires attention.
How the Flow Cal 5000 Liquid Flow Meter Increases Productivity
This digital liquid flowmeter does not require constant supervision. Using it frees up technicians to perform other tasks.
Because it is portable, the Flow Cal 5000 flow meter can be transported throughout the lab to conduct tests elsewhere. For example, at one installation a single flowmeter is being used to service 100 HPLC systems.
In another case, a pharmaceutical industry service provider transports the unit between different client locations. The spokesperson noted that a flow analysis can be completed in less than five minutes, including the all-important data output for record keeping. This works out to a 15- to 20-minute savings in time over the gravimetric method.
The FlowCal 5000 HPLC Liquid Flow Meter Close-up
- Ideal for IQ OQ PQ and troubleshooting
- Accurate to 1% of reading with guaranteed linearity from 0.05 to 25.00 ml/min
- Supplied gravimetrically calibrated at 1.0 ml/min. Multi-point calibration available.
- Durable and easy to use with any HPLC pump
- Usable with all standard HPLC solvents
- Easy diagnosis of leaking piston seals or malfunctioning check valves
- Automatic Data Transfer via RS232 or with a new optional battery powered mini printer
3 Modes of operation:
- Printer Mode: liquid flow readings are displayed on the LCD and output to a printer if one is connected. A running average option is available in this mode
- Terminal Mode: in this mode the liquid flowmeter is controlled by the terminal or PC. Extra commands for averaging any number of readings are included.
- Test Mode: this mode allows the user to test the display, valve and RS232 interface and also display the calibration date.
FlowCal 5000 Specifications
- Reading Update Time
- 15 sec @ 2 ml/min
- 25 sec @ 1 ml/min
- 45 sec @ 0.5 ml/min
- Measuring Volume - 140 μl
- Priming Volume - 250 μl
- LCD Display - (12.7mm)- 4 digits and 3 status symbols
- RS232 output - (6 digits) XX.XXXX ml/min
- Size - 5.4 x 3.0 x 1.8 inches (138 x 76 x 45 mm)
- Weight - 320g, 12 oz
Flow Rate, ml/min
Your Flow Cal 5000 flow meter is shipped with the following:
- Mains ‘wall block’ power supply with a choice of 240V 3 pin UK, 230V 2 pin European or 100V 2 pin USA/Japan.
- RS232 input/output cable: 8way mini-din plug to PC COM port 9 pin female.
- UKAS (equivalent to NIST) traceable single point flow calibration certificate
- Universal mounting kit: allows free standing mount, wall mounting, ‘stack system’ mounting and bottle top mount.
- Black plastic carrying case with foam inserts, cleaning kit and mounting kit.
Optional Thermal Printer
A miniature thermal printer for the FlowCal 5000 Digital Liquid Flow Meter will print all readings and error messages output from the flowmeter via the built-in RS232 interface.
- Compact and stylish design
- Easily loaded with paper
- Built-in RS232 interface
- Strong case design
- Supplied with re-chargeable battery
- Supplied with power/charger lead with Print on/off switch built-in to plug directly into the flowmeter
- No extra power supply required – unit uses the flowmeter power supply
- Supplied ready to work with the FlowCal 5000 liquid flow meters set to the default settings
- Readings printed to four decimal places