How to avoid installation mistakes when working with Model 62-9 Insertion Probe Flow Meters

Thermal Instrument Model 62-9/9500P inserted into pipe

Installed Model 62-9/9500P Insertion Probe

Over the years our technicians have fielded numerous questions about meter performance and many of those solutions come back to some common installation mistakes. When it comes to Thermal Instrument Mass Flow Meters there are a couple things that you can check very easily when you experience a problem or suspect something is not 100% accurate with the measurement values. Here are a couple of suggestions from our technicians to common questions we receive.

Scenario: I know I have flow, but Flow Meter is not measuring anything.


Check to make sure that the insertion probe flow meter is properly inserted into the line to the correct depth. With Thermal Instrument Model 62-9 insertion probes, the sensors are located on the bottom 3” section of the probe closest to the tip. Make sure that the tip of the probe is inserted to the proper depth depending upon the line size. Ideally you want that sensor right in the middle of the flow profile. Additionally, check all your connections and make sure that the meter is powered on and that the output cables are securely attached at the transmitter.

Scenario: As my flow rate increases, the meter seems to be consistently reading lower


First, make sure that the sensors are facing into the flow stream. Thermal Instrument marks each Model 62-9 with a Flow Direction Arrow just underneath the transmitter condulet. Make sure that the arrow is facing in the same direction as the flow. Next, if you are running an application that is dirty or has particulates in the flow stream, check to make sure that the sensor area does not have a coating on the meter. Our meters are designed so that they can be removed from the line (please make sure you follow local safety regulations) and then simply wipe any buildup off of the probe that may have accumulated down at the bottom where the sensors are located.

For more information visit our FAQ page or feel free to contact us to speak with one of our technicians. Phone: 215-355-8400 then Option 3 on phone menu for Tech Support.

Thermal Instrument Company
217 Sterner Mill Road
Trevose, PA 19053
P: 215-355-8400 | F: 215-355-1789

About Thermal Instrument Company 

Thermal Instrument Company (TIC), established in 1959, headquartered in Trevose, Pennsylvania, provides leading edge instrumentation solutions for measuring the mass flow rate of liquids and gases.  TIC has been providing flow measurement solutions for more than 60 years to a variety of industries throughout the globe, and has an installed base in excess of 20,000 thermal mass flow measurement devices. TIC has provided flow measurement solutions for: natural gas to boilers, furnaces, and in pipelines; clean gases used in manufacturing processes; methane and landfill gas from wastewater and landfill sites; water for cooling and pharmaceutical applications; and numerous other liquids and gasses used in environmental and industrial processes. TIC offers a full line of thermal mass flow meters and flow switches available in either an unobstructed path in-line model, or as an insertion probe model. For more information about Thermal Instrument Company’s flow measurement solutions, please visit our website or contact one of our sales representatives.