TSI Thermal Mass Flowmeter Models 4140/4143

Chapter 1: Unpacking and Parts Identification

Carefully unpack the instrument and accessories from the shipping container. Check the individual parts against the list of components in Table 1. If any parts are missing or damaged, notify TSI immediately.

Table 1. List of Components

*Other than the specifications in Appendix A, all references to 4140 and 4143 in this manual apply to the 41403 and 41433, respectively.

Table 2. Optional Accessories

Figure 1-1 Model 4140/4143 Mass Flowmeter

1. On/Off Switch, 2. Display, 3. Mounting Inserts (2), 4. DC Power Input, 5. Flow Inlet, 6. Computer Serial Interface, Analog Output, and Optional Power Input Connection

Chapter 2: Setting-Up

Supplying Power

The flowmeter can be powered in one of two ways: through the power jack using the supplied AC adapter or through the mini-DIN connector. The DC power input connector is shown below along with the power requirements.

Power Supply: 7.5 VDC ± 1.5 V, 300 mA maximum

Figure: DC INPUT

When supplying power through the optional TSI interface cable, line up the arrow on the connector with the bottom side of the flowmeter. Flowmeter connector pin-out designations are shown below.

Table 3. Connector Pin-out and Color Code for TSI Cable PN 1303584

Connecting Filter and Flow Tubes

The Model 4140/4143 has a thermal sensor exposed to the gas flow that must be protected from foreign matter and particles. TSI supplies a filter that should be connected to the inlet of the flowmeter, however, any filter will work as long as it has a minimum efficiency of 99.9%.

Caution: ⚠️ Always use a filter on the inlet of the flowmeter. Failure to filter the gas flow may change the calibration and/or permanently damage the sensor.

Note: Flow direction is identified by the large arrow printed on the bottom side of the flowmeter.

After attaching the filter, connect the flow tube to the inlet of the filter. Connecting a tube to the outlet of the flowmeter will create back pressure. See Appendix A for flowmeter accuracy specifications when operating at various pressures. In general, minimize back pressure on the flowmeter to maintain higher accuracy.

RS232 Configuration and Operation

Many flowmeter operating parameters can be easily configured through the RS232 serial port. Likewise, the flow rate, temperature, pressure, and volume can be read through the serial port. Refer to the Series 4000/4100 RS232 Serial Command Set manual for a detailed description of the commands and command syntax.

RS232 Settings:

• Baud Rate: 38.4 k
• Data Bits: 8
• Parity: None
• Stop Bits: 1
• Flow Control: None

Table 4. Changeable Operating Parameters

Configuration Software

TSI has several software utilities to help you communicate with your flowmeter to change parameters and to obtain flow data. You can download the latest versions of these at no charge from our web site.

1. If you only want to change one or more of the operating parameters shown in Table 4 (above), the easiest way is to use the software utility called "TSI setup." This uses convenient drop-down menus to help change these parameters. After you have made your changes, be sure to click on "Send" to store the changes in the flowmeter's memory.

Figure: TSIsetup Window (Shows fields for Gas, Sample Rate, Flow Units, Analog Span, Analog Zero, Display Update Rate, Display Scroll Mode, and buttons for Close, Default, Read, Send, About, Help)

2. If you want to communicate directly with the flowmeter using the basic RS232 commands shown in the Serial Command Set Manual, you can use a terminal program. HyperTerminal is a common terminal program that is included with most versions of the Microsoft operating system. Setting up HyperTerminal to communicate with your flowmeter can sometimes be confusing. You can download a document from our web site that helps you configure HyperTerminal. Download the document called "Using HyperTerminal to communicate with TSI Flowmeters."

3. If you plan to develop a more sophisticated program for data collection and control using LabVIEW, you can download a demonstration program called “Real-time Demo Program” and the source code "Source Code for Real-time Demo Program.” This program is intended to be a basic demonstration program and not a practical laboratory tool. It does, however, have a convenient implementation of the VOLUME measurement function that can be useful for basic tests.

Chapter 3: Operation

Caution: ⚠️ TSI flowmeters are not medical devices under FDA 510k and in no situation should they be utilized for human respiration measurements.

Overview

The Model 4140/4143 Flowmeter measures mass flow rate, temperature and absolute pressure of the gas inside the flow tube. All measurements made by the Models 4140/4143 are NIST traceable.

ON/OFF Switch

Slide the switch to the ON position. The power switch is marked in the international symbols '|' for on and 'O' for off.

Warm-up Time

The flowmeter will provide readings immediately upon power-up. Recommended warm-up time of the flowmeter is 5 minutes.

Flow Rate Measurement

Flow rate data can be obtained from the Model 4140/4143 through the LCD display, RS232 serial port, or the linearized analog output. The analog output is a 0 to 10 volt DC linear signal representing 0 to 20 Std L/min. The analog output scaling is user selectable. Refer to the Series 4000/4100 RS232 Serial Command Set manual for instructions on how to obtain flow data through the serial port.

Gas calibrations (air, 100% O2, 100% N2 or 100% N2O) can be selected through the RS232 serial port. Refer to the Series 4000/4100 RS232 Serial Command Set manual. The LCD display will indicate the calibration being utilized: air, O2, N2, or N2O.

Flow can be displayed in units of standard liters per minute (Std L/min*) or in volumetric units of liters per minute (L/min). Refer to Appendix B for a description of the two measurements. Selecting between the two measurements is accomplished through the serial port. Refer to the Series 4000/4100 RS232 Serial Command Set manual for instructions on how to select between flow units.

*TSI instruments defines standard conditions as 21.1°C (70° F) and 101.3 kPa (14.7 psia, 1 bar).

The Model 4140/4143 has an independent temperature sensor in the flow tube to measure the gas temperature. The temperature sensor is used for temperature compensation of flow rate and for converting flow from standard to volumetric units. Temperature can also be displayed on the LCD and is available through the RS232 serial port in the units of degrees Celsius (°C).

Note: At low flow rates, the temperature inside of the flow tube will increase because of the heat generated by the thermal flow sensor. This effect is normal and the temperature of the incoming gas will be measured once flow resumes.

Pressure Measurement

The Models 4140/4143 measure absolute pressure near the outlet of the flowmeter in the SI units of kilo-Pascals (kPa). Pressure measurements are required when converting from standard to volumetric flow. Absolute pressure can be displayed on the LCD and is available through the RS232 serial port.

Select Measurement Displayed

By using RS232 commands the LCD display can be set up to continuously display either flow rate, temperature, or pressure. See the SDMm command in the Series 4000/4100 Serial Command Set manual.

Display "Scroll" Mode

By using RS232 commands the LCD display can be set up to continuously scroll between flow rate, temperature, and pressure. The scroll rate is adjustable and the user can specify the parameters to be displayed. See the SDMFTPn command in the Series 4000/4100 Serial Command Set manual.

Volume Measurement

These flowmeters measure total volume by integrating flow over time. This is a calculated measurement performed by the flowmeter and is only available using the RS232 serial port. Volume is not displayed on the LCD display. Refer to the Series 4000/4100 RS232 Serial Command Set manual for instructions on using the volume function.

Chapter 4: Maintenance

Flow Sensor

Periodically inspect the flow sensor by looking into the outlet of the flowmeter. Remove dust, particles and fibers from the sensor with clean, dry compressed air. The flow sensor will break if touched. Never run liquids through the flowmeter and never touch the sensor with a brush. Dust or other deposits on the flow sensor will degrade the 4140/4143 flowmeter's flow accuracy.

Caution: ⚠️ The flowmeter must be switched off for cleaning. Only use clean, dry, compressed air when attempting to remove contamination from the sensor.

Re-certification

To maintain a high degree of confidence in the measurements made by the Model 4140/4143, TSI recommends that the instrument be returned to TSI every 12 months for re-certification. The flowmeter will be recalibrated and returned with a certificate of calibration to US National Institute of Standards Technology (NIST) traceable standards. This "annual checkup" assures you of consistently accurate readings; it is especially important in applications where strict calibration records must be maintained.

Cases

If the instrument case or storage case needs cleaning, wipe it off with a soft cloth dipped in isopropyl alcohol or mild detergent. Never submerge the flowmeter or allow liquids to enter the flow tube.

Storage

When storing the flowmeter, always cover the ends of flow tubes with the caps provided to prevent dust or other foreign matter from entering the tube.

Chapter 5: Troubleshooting

Table 4 lists the symptoms, possible causes, and recommended solutions for common problems encountered with Series 4100 flowmeters. If the symptom is not listed, or if none of the solutions solves the problem, consult TSI.

Table 4. Troubleshooting

Appendix A: Specifications*

Flow Measurement

• Measurement Range: 0.01 to 20 Std L/min.
• Accuracy: Air and 100% O2: 2% of reading or .005 Std L/min, whichever is greater.
• 100% N2: 3% of reading or .010 Std L/min, whichever is greater.
• 100% N2O (41403 and 41433 only): 3% of reading or .010 Std L/min, whichever is greater.
• Accuracy stated at standard conditions (21.1°C and 101.3 kPa)
• See notes 1 through 6 below.
• Resolution (Display): 0.001 Std L/min between 0.01 and 9 Std L/min; 0.01 Std L/min between 9 and 20 Std L/min
• Response: Less than 4 msec, 63% of final value at full scale flow

Temperature Measurement

• Measurement Range: 0 to 50°C
• Accuracy: ±1°C, at flows greater than 1 L/min. See note 2 below.
• Resolution (Display): 0.1°C
• Response: Less than 75 msec, 63% of final value for 20°C step change in temperature at full scale flow

Static Pressure Measurement (Measured inside flow tube near the exit)

• Measurement Range: 50 to 199 kPa Absolute
• Accuracy: +1 kPa, See note 7 below.
• Resolution (Display): 0.1 kPa
• Response: Less than 4 msec.
• Over Pressure: 63% of final value for 30 kPa step change
• Burst Pressure: Tested to 690 kPa without rupture. Do not exceed 690 kPa.

Pressure Drop

See Chart.

Figure A-1 Pressure Drop (Graph showing Pressure Drop vs. Flow (SLPM) for 4140, 4140 with filter, 4143, and 4143 with filter)

Volume

• Measurement Range: 0.001 to 99.99 Liters
• Accuracy: Air and 100% O2: 2% of Reading at flows greater than 2.5 Std L/min
• 100% N2: 3% of Reading at flows greater than 2.5 Std L/min
• 100% N2O (41403 and 41433 only): 3% of Reading at flows greater than 2.5 Std L/min
• See notes 1 through 5 below.

Instrument Temp. Range

• Operation, Ambient: 0 to 50°C
• Storage, Ambient: -20 to 60°C

Gas Calibrations

Air, O2, N2, N2O (41403 and 41433 only), User selectable through serial port

Physical Dimensions

• External Dimensions: See Diagram
• Tube Adapters (Inlet & Outlet): Model 4140/41403: 0.25 inch O.D. straight; Model 4143/41433: 0.375 inch O.D. straight
• Weight: 86 grams
• Flow Body Material: Polycarbonate

Computer Interface

• Connector: 8 pin mini-DIN
• Type: RS232 Serial
• Baud Rate: 38,400
• Data Bits: 8
• Parity: None
• Stop Bits: 1
• Flow Control: None

Analog Output (Flow Only)

• Range: 0 to 10 V
• Resolution: 13 bit
• Maximum Current: 10 ma
• Flow Accuracy: See note 6 below.

Power

AC adapter or power supplied through mini-DIN 7.5 VDC ± 1.5 V, 300 mA maximum

Notes:

1. Accuracy stated at standard conditions of 21.1°C and 101.3 kPa.
2. Add an additional 0.0003 Std L/min or 0.075% of reading, whichever is greater, per 1°C away from standard conditions when operating within the range of 0°C to 50°C.
3. Add an additional 0.015% of reading per 1 kPa above 101.3 kPa or Add an additional 0.022% of reading per 1 kPa below 101.3 kPa when operating within the pressure range of 70 kPa to 101.3 kPa.
4. Accuracy stated with gas temperature and flow body temperature within ±10°C of one another.
5. Volumetric flow rate is calculated from the mass flow measurement. Add an additional 0.25% of reading to the flow accuracy to account for the uncertainty in measuring gas temperature and pressure.
6. For analog output, accuracy offset increases from 0.005 to .02 Std L/min.
7. Add uncertainty of 0.2 kPa for every 10°C away from 21.1°C.

*Specifications subject to change without notice.

Figure A-2 Model 4140/4143 Dimensions (Diagram showing dimensions and mounting details of the flowmeter)