We are open Monday – Friday 8:00 AM to 5:00 PM EST / EDT. You can easily reach us via telephone at 215-355-8400 or via email at: Office@thermalinstrument.com

The most successful way to get help from our technicians is to have your serial number and/or part number of the item you are referencing. This will greatly help our technicians quickly research and resolve your question or issue.

Package the flow meter(s) and send to our address below with the following information: Contact Name, Phone, Email, Return Address, PO# (If required), and Reason for Return (i.e. Recalibration, Need Certificate, As Found / As Left, etc.)

Thermal Instrument Company
Attn: Repairs/Recalibrations
217 Sterner Mill Road
Trevose PA, 19053 USA

No. We do not require RMA numbers to return meters. If you are required to have an RMA number then just use the Serial Number of the meter(s) since they are unique to the meter(s). Our Serial Numbers can be found on a metal tag on the back of the condulet or etched onto the body of the flow meter.

Typical return time is about 3 to 4 weeks. If you require a faster turn-around time, note the requirement on the paperwork that will be sent with the meter and we will do our best to accommodate.

Typical delivery is 4 – 6 weeks from the time a PO# is issued and an order acknowledgement is received. However, we can offer an expedited solution depending on the requirements and specifications of the application. Please contact us to see if we can offer an expedited solution.

We ship our orders via UPS. We have arrangements with FedEx, DHL, and numerous other carriers if you have a preference.

Upon arrival to the landfill site, a steady flow rate must be set in the line where the flow meter is installed. Steady flow rate at most landfills can be challenging but even a flow rate fluctuating +/- 0.2 “ H2O is tolerable but a flow rate fluctuating above +/- 0.4 “ H2O should be avoided.


The gas mixture percentage of Methane, CO2 and Oxygen is requested for each line checked. This information will go into correcting the Pitot tube flow calculation.


Establishing whether a flow meter is controlling the system or just monitoring the system is a must. No problems will occur if the meter is just monitoring the system but if a meter is controlling then the next step is to determine if the system can be placed into manual mode. This is requested so to know if a meter can be removed from the line for inspection and in case the meter’s line port is needed for the Pitot tube.


The meter installation is inspected. The installation check includes proper meter orientation, insertion length, correct line size, and correct upstream and downstream distance (10 pipe diameters upstream and 5 pipe diameters downstream).

If any part of the installation is in error, the meter indication is logged (before) and, if possible, the installation is corrected and meter indication logged (after).


The line pressure and gas temperature is established.


For best results, the Pitot tube requires two ports in the line, one for horizontal data and one for vertical data. The two ports are really for times when proper straight run cannot be established. If the proper straight run is established then really only one port is required since both port readings will only repeat themselves.

These ports should also be located upstream of the flow meter so that the flow meter will not interfere with the Pitot tube readings. These ports should be located no less than 6” away from the shaft of the meter. This is to make sure the Pitot tube is not blocked by the flow meter’s condulet head.

Of course there are times when a line has already been established and extra ports cannot be made at the time of field calibration. During these times, is it possible that the flow meter’s port can be used (if the L shaped Pitot tube can fit through the port).


Once the Pitot tube is installed into the line, the distance between all the way to the far side of the inside pipe to the near side of the inside pipe is measured by making “marks” on the Pitot tube. This distance is used to determine the locations across the pipe to take flow measurements. With the radius (R) established from this distance, the locations are calculated into five spots from the center line: 0.316 R, 0.548 R, 0.707 R, 0.837 R, and 0.949 R. These five spots are marked on both sides of the center to establish a total of 10 flow measurements across the line.

At each flow measurement, a Pitot tube reading is established by averaging over a period of time, usually about 30 seconds but could be longer or shorter depending on the flow fluctuations, and is then logged.

Once the 10 data points are logged, the process repeated, if needed, for the other direction across the line (vertical to horizontal or vise versa).


The data points are then averaged into one flow rate.

The landfill flow rate is calculated from the averaged flow rate, gas mixture, line pressure and temperature. This flow rate is standardized to 60°F at 1 ATM.


This calculated flow rate is compared to the flow meter indication. Flow rate error is then calculated by taking the flow rate difference between the flow meter indication and Pitot tube calculated flow rate and dividing by the flow meter’s full scale flow rate calibration. The EPA states the flow meter should be within 5%. Thermal Instrument Field Technicians hold the meter to 1% error to cause an adjustment. The adjustment is done by the ZERO potentiometer located on the flow meter.


The meter Certification follows later once the technician returns to the factory.

Our Landfill Gas meters are calibrated to a wet basis of 50/50 percentage mixture of Methane and CO2 with a tolerance of +/- 10% variance

Landfill gas is calibrated to 60 °F (16 °C) at 1 ATM unless otherwise stated in the calibration data.

Standard landfill gas meter temperature range is 40 to 200 °F  (4 to 93 °C), unless requested otherwise.

Our meters require 10 pipe diameters upstream and 5 pipe diameters downstream of straight run.

If you feel the best location you have for a meter is under this requirement then just let us know. We can calibrate a meter with your plumbing situation but it will be only good for just that location.

Minimum of 10 pipe diameters of straight run ahead of the meter and 5 pipe diameters after.

Meter can be mounted on top of the line, 12 o’clock position, or through the sides of the line, 3 or 9 o’clock position. but not up through the bottom of the line.

Meter can be mounted in a vertical or horizontal line.

For Serial Numbers of 2011xxx or less, the probe is mounted in the line with the face of the arrow facing up-stream. The arrow is etched on the probe shaft just underneath the condulet head.

For Serial Numbers of 2012001 or higher, the probe is mounted in the line with the arrow pointing in the direction of flow. The arrow is etched on the fitting just underneath the condulet.

The insertion length of the probe inside the line is:

Line Sizes 1 1/2″ to 2″ – Gently insert to bottom of line then withdraw 1/8″

Line Sizes 2 1/2″ to 7″  – Gently insert to bottom of line then withdraw 1/4″

Line Size 8″ & Greater– Insert halfway into line then insert 3″ more

We recommend a calibration check every 12 to 18 months.

Our meters are good with moisture up to the point where it forms droplets onto the sensor location on the meter. Moisture droplets will cause the meter to indicate high and noisy until the droplets either fall off or evaporate, which then the meter will indicate back to normal.

Yes. All of our meters are calibrated with temperature compensation to the temperature minimum and maximum conditions where the meter will be installed.

Pressure has no affect on our flow meters calibrated for liquids. For meters calibrated for gases, pressure has to change more than (+/-) 15 ATM before affecting meter output. We do need to know the maximum pressure where the meter will be installed to make sure the meter will have the proper and safe process connection.

Our standard is 70 °F (21 °C) at 1 ATM unless otherwise stated.

No. The mA output is self powered. No external power needed.

Yes. This Model does come with a 24 VDC power supply that you can use for the mA output or you can use a 24 VDC power supply of your own.

Yes, you will need to wire both sets of connections to 110 VAC. One set is for the 9200B itself while the other is for powering up the flow element. You can just simply jumper the two sets if you only have one 110 VAC available.

Yes. We have many customers that utilize our field service in order to minimize any down time in production at their site. Our Field Service Engineers will travel to your location, diagnose, re-calibrate or troubleshoot the problem, and have your operation running again in minimum time.  For our Landfill customers, we have the ability to provide on-site re-calibration and certificate services in order to maintain compliance with United States EPA regulations. Please contact Thermal Instrument at 215-355-8400 to schedule your on-site field service at your convenience.

Standard Configuration
12 Volt DC pulse with a 20 millisecond on time and one pulse per specified flow range.

The three variables or options are:
Option #1 – Voltage pulse or dry contact closures output
Option #2 – Length of pulse 20 millisecond standard. Can be shorter or longer. For example, 5 millisecond, 100 millisecond, 1 second. Etc.
Option #3 – Pulses per unit of Flow rate. For example, 1 pulse per flow unit, 10 pulses per flow unit. Etc.

The three variables cannot be changed in the field, therefore Thermal Instrument Co. needs to know exact variables needed to accommodate the equipment interface.

(1) Thermal Instrument Co. warrants that the products furnished under this Agreement will be free from defects in material and workmanship for a period of four years from the date of shipment.  The customer shall provide notice of any defect to Thermal Instrument Company within one week after the Customer’s discovery of such defect.  The sole obligation and liability of Thermal Instrument Company under this warranty shall be to repair or replace, at its option and discretion, without cost to the Customer, the defective product or part.

(2) Upon request by Thermal Instrument Co, the product or part claimed to be defective shall immediately be returned at the Customer’s expense to Thermal Instrument.  Replaced or repaired products or parts will be shipped to the Customer at the expense of Thermal Instrument.  Thermal Instrument Company shall have the right of final determination as to the existence and cause of defect.

(3) There shall be no warranty or liability for any products or parts that have been subject to misuse, accident, negligence, acts of God, lightning strikes, flooding, or failure of electric power or modification by the Customer without the written approval of Thermal Instrument.  This warranty does not cover damage caused by customer’s exposure of the goods to corrosive or abrasive environments.  Final determination of warranty eligibility shall be made by Thermal Instrument Company.  If a warranty claim is considered invalid for any reason, the Customer will be charged for services performed and expenses incurred by Thermal Instrument in handling and shipping the returned unit.

(4) The liability of Thermal Instrument Company shall be limited to replacing or repairing, at its option, any defective parts which are returned.  Labor and related expenses incurred by the Customer to install replacement parts are not covered by this warranty.

(5) For replacement parts supplied or repairs made during the original warranty period, the warranty period for the replacement or repaired part shall terminate with the termination of the warranty period of the original product or part.

(6) The use of Thermal Instrument Company products are under exclusive control of the buyer. No warranty is given for the calibration, accuracy or workmanship of product into which Thermal Instrument Company products are installed.  Thermal Instrument Company can only be held responsible for the calibration and accuracy of the product supplied by Thermal Instrument themselves as the manufacturer.  Thermal Instrument Company specifically denies any liability arising from the buyer’s application of Thermal Instrument Company products including any physical injuries or death arising directly or indirectly out of or in connection with the manufacture, sale, use, or defect of the products sold hereunder.

(7) No warranty is made with respect to custom equipment or products produced to Buyer’s specifications except as specifically stated in writing by Thermal Instrument Company and contained in the agreement.


Modbus ASCII and Modbus TCP are not supported. Naming conventions for the RS-485 interface are per the latest revisions of the Modbus over Serial Line Specification and Implementation Guide V1.02 and the Modbus Application Protocol Specification V1.1b3.

RS-232 Communications settings
The meter is preconfigured for serial communications at 9600 baud, even parity, 8 data bits, 1 stop bits. These settings can be changed in the field by using the TICO Parameter Setup Utility software tool.

Slave ID
The unit is shipped from the factory with the Slave ID set to 1.  This setting can be changed in the field by using the TICO Parameter Setup Utility software tool.

Modbus Function Codes Supported
The only function supported in this version is the Read Holding Register, as described below.

Reg TypeModbus AddrData TypeDescription
Holding40001FloatMass flow in Eng Units
Holding40002FloatMass flow in Eng Units
Holding40003FloatMass flow in Eng Units
Holding40004FloatMass flow in Eng Units

The float values are sent in the normal order mode as accepted by most Modbus masters.  The float values can be changed to Swap Word Order, Swap Byte Order, or Swap Both Word and Byte Order by using the TICO Parameter Setup Utility software tool.