Tips & tricks: How to simplify troubleshooting in your GC lab using Agilent ADM Flow Meter
Paul Tripp, Agilent Gas Management Supplies Product Manager
Flow meters provide peace of mind to any Gas Chromatography (GC) lab in the business of providing their customers with an external reference for verifying flows. For routine maintenance, the flow meter is a valuable instrument for troubleshooting detector problems. Comprehensive testing of the new and improved Agilent ADM Flow Meter demonstrates its an effective tool for busy contract GC labs−providing innovative capabilities not found in older models or competing products. Additionally, the Agilent ADM Flow Meter is an easy to use, cost-effective solution.
In this article, our experts offer useful tips and tricks for simplifying your GC lab troubleshooting protocols using the Agilent ADM Flow Meter.
A better way to simplify recalibration of your flow meter
Figure 1. Removable calibration cartridge for simple, easy replacement.
TIP: Ideal for measuring composite gases, the Agilent ADM Flow Meter is very easy to maintain, due to its removable calibration cartridge (Figure 1). Instead of returning the entire meter to a third party for recalibration, you simply replace the cartridge once a year with a new NIST-calibrated cartridge to keep the Agilent ADM Flow Meter compliant.
Currently, to recalibrate a meter you must first receive a quote from a third party vendor. This is followed by time-consuming paperwork involving how and where the meter was last used. The completed forms are mailed to the vendor, leaving your lab waiting for a shipping container. Once the meter is returned, the wait begins for the meter to be recalibrated—which can take up to 2 weeks. Additionally, if any damage to the valve or speaker is found, you are liable for additional costs to repair.
There is a better way. With the revolutionary Agilent ADM Flow Meter, simply order a part number that includes a new recalibrated cartridge and replace it in just seconds in your lab. Your troubleshooting steps are streamlined:
Reduce downtime by not sending away the meter for recalibration or repair.
Eliminate geographic restrictions. No need to deal with third party shipping restrictions.
No time consuming paperwork. Just order a new NIST-calibrated cartridge.
Increase accuracy in reporting. Volumetric flowmeters do have some drift over long periods time (>1 year). The Agilent ADM Flow Meter built-in calibration timer automatically warns when the calibration cartridge needs replacing.
Types of flow measurement and tips on modes
Figure 2. Agilent ADM Flow meter in volumetric flow mode.
The ADM Flow Meter provides two different types of flow measurement: volumetric flow (mL/min) and mass flow reported in standard cubic centimeters per minute (sccm). Mass flow values are calculated from the volumetric measurements by correcting for ambient temperature and atmospheric pressure and reporting the flow rate referenced to 0 °C and 1 atmosphere of pressure.
Volumetric flow mode: This is the default mode on power up. In this mode, the volumetric flow rate is displayed in mL/min (Figure 2).
Mass flow mode: In this mode, the volumetric flow rate is corrected taking into account the current atmospheric pressure and ambient temperature. The flow rate is displayed in sccm (standard cubic centimeters per minute).
Split mode: In this mode, you can store a flow measurement as a reference value, and then compare subsequent flow measurement values as a ratio of the current measurement to the reference measurement. This is useful when troubleshooting a GC Inlet.
Storing flow measurements: When in the volumetric flow mode or mass flow mode, up to four flow values can be stored on the screen for reference later.
Determining the best way to capture data on flow testing
TIP: Use the Agilent ADM Flow Meter to communicate via a USB port. Data from your flowmeter is easily captured and uploaded by simply connecting the USB port to your computer—using the included USB cable. Note: the ADM Flow Meter USB driver is needed for the instrument to communicate with your PC.
Why are ADM Flow Meters more effective than soap bubble meters?
Figure 3. Conducting a reading with Agilent ADM Flow Meter.
TIP: When compared with readings from the Agilent ADM Flow Meter, measurements taken with bubble-type flowmeters may show a difference. As a consequence of the ideal gas law, measurements made with both soap bubble meters and the ADM Flow Meter are temperature sensitive. However, bubble-type flowmeters add water vapor to the gas being measured, which introduces error into the flow rate measurement. This is not a problem with the Agilent ADM Flow Meter (Figure 3).
Agilent offers a wide selection of GC solutions and resources
As with any Gas Chromatograph, an external reference for verifying flows and troubleshooting detector problems is always needed. The Agilent ADM Flow Meter has everything to address those needs while simplifying calibration.