Extech Extech SDL350 Manual

99 Washington Street
Melrose, MA 02176
Phone [phone]

User's Guide

Visit us at www.TestEquipmentDepot.com

Toll Free 1-800-517-8431

Hot Wire Thermo-Anemometer
with Datalogger

Model SDL350

Hot Wire

5

Introduction

Congratulations on your purchase of the Extech SDL350 Hot Wire Thermo-Anemometer
Datalogger. This meter displays and stores air velocity and temperature readings. Temperature
readings from the thermometer built into the probe or from an externally connected type K or J
thermocouple temperature probe can be displayed and recorded. Data is stored on an SD card for
transfer to a PC. This meter is shipped fully tested and calibrated and, with proper use, will provide
years of reliable service.

Safety

International Safety Symbols

This symbol, adjacent to another symbol or terminal, indicates the user must refer to the
manual for further information.

Description

METER AND HOT WIRE PROBE

1. Thermocouple input

2. Hot Wire input plug

3. Display for air velocity and air flow readings

4. Units of measure

5. HOLD / Backlight

6. MAX-MIN key

7. SET and Clock

8. PC interface jack

9. Reset key

10. Power Adaptor jack

11. SD card slot

12. ENTER and LOG key

13. Down ▼arrow and FUNCTION key

14. Up ▲ arrow and UNIT key

15. Power ON-OFF

16. Temperature reading with units of measure

17. Hot Wire probe cable

18. Telescoping probe handle

19. Protective cover (sensors underneath)

20. Colored dot must face air flow

HOT WIRE PROBE TOP (detail)

1. Air stream must face into colored dot

2. Air velocity sensor

3. Sliding protective cover OPEN position

4. Sliding protective cover CLOSED position

5. Temperature sensor

NOTES:

Battery compartment, tilt stand, and tripod mount are located on the rear of the instrument.
Items 8, 9, and 10 are locat ed behi nd the sna p-off compar tment cover o n ri ght side o f met er.

key

key

key

16

15
14

13
12

1

1

Hot Wire

5

11

2

3

20

2

3
4

5
6
7
8
9
10

4

5

19

18

17

2 SDL350-EU-EN-V1.1-9/11

Operation

Power ON-OFF

Power the meter ON or OFF by pressing and holding the power key

Meter Functions

This meter has three modes of operation: Air velocity (with temperature), thermocouple
temperature, and Air Volume (CFM/CMM). Press and hold the FUNCTION key for at least 1.5
seconds to switch from one mode to the other.

• Air Velocity plus Temperature mode; meter displays An icon.

• Type K or J thermocouple temperature mode (meter displays tP icon).

• Air Flow (Volume CFM/CMM) meter displays F-US or F-EU depending how the meter is set up

for units of measure for area; refer to the SETUP mode for details.

Air Velocity plus Temperature Mode

1. Select the Air Velocity and Temperature mode as described above.

2. Connect the vane probe to the meter’s probe jack (top right of meter) via the probe plug.

3. Hold the probe by its handle and allow the air flow to enter the sensor area. Note that the air
flow must face the probe’s colored dot.

4. The meter will display the air velocity measurement (upper display area) and the air
temperature (lower display area).

Changing the Air Velocity Unit of Measure

This meter offers five (5) units of measure selections for air velocity: m/s (meters per second), FPM
(feet per minute), Km/h (kilometers per hour), knots, and mph (miles per hour).

1. Press and hold the UNIT key for at least 1.5 seconds to switch from one unit of measure to
another.

2. Note that pressing and holding the UNIT key continuously allows for quicker scrolling. Release
the key when the desired unit of measure is displayed.

Thermcouple (Type J or K) Temperature Mode

1. Select the Thermocouple Temperature mode using the FUNCTION button as described above.

2. The meter will display a ‘J’ or a ‘K’; on the left side of the display indicating the selected type.
To change the thermocouple type, refer to the Setup Mode section.

3. Connect a Type J or Type K thermocouple to the meter’s sub-miniature thermocouple jack (top
of meter on the left).

4. Hold the thermocouple in the air in the area to be tested.

5. The meter will display the thermocouple temperature in the main display area.

6. To change the temperature unit of measure (°C and °F) refer to the Setup Mode section.

for at least 1.5 seconds.

3 SDL350-EU-EN-V1.1-9/11

Air Flow (Volume CFM/CMM)

1. First measure and note the area of the duct or other passageway under test in square feet or
square meters. For rectangular ducts, area is calculated using Length * Width; for circular
ducts use 3.14 * R

2

.

2. Enter the area value in the SETUP mode (refer to SETUP mode section for details).

3. Select the Air Volume mode on the meter as described earlier using the FUNCTION key.

4. Connect the hot wire probe to the meter’s probe jack (top right of meter) and slide open the
probe’s protective cover to expose the hot wire sensor. Close the protective cover when the
probe is not in use.

5. Hold the probe by its handle and allow the air flow to pass through the sensor area. Note that
the air flow must face the probe’s colored dot. Refer to the meter and probe diagram section.

6. The meter will display the air volume measurement in the upper display area and the selected
unit of measure (US or EU) in the lower display area (F-US for CFM; F-EU for CMM). CFM
represents cubic feet per minute and CMM represents cubic meters per minute.

Data Hold

To freeze a measurement on the display, press the HOLD key momentarily. The meter will emit a
beep, the reading will hold, and the HOLD display icon will switch on. Press the HOLD key again to
release the display and exit the Data Hold mode returning the meter to the normal operating mode.

MAX-MIN Readings

For a given measurement session, this meter can record the highest (MAX) and the lowest (MIN)
readings for later recall.

1. Press the MAX-MIN key momentarily to access this mode of operation (REC icon appears)

2. The meter is now recording the MAX and MIN readings.

3. Press the MAX-MIN key again to view the current MAX reading (MAX icon appears). The
reading on the display is now the highest reading encountered since the REC icon was
switched on (when the MAX-MIN key was first pressed).

4. Press the MAX-MIN key again to view the current MIN reading (MIN icon appears). The
reading on the display is now the lowest reading encountered since the REC icon was
switched on (when the MAX-MIN key was first pressed).

5. To exit the MAX-MIN mode, press and hold the MAX-MIN key for at least 1.5 seconds. The
meter will beep, the REC-MAX-MIN icons will switch off, the memory will clear, and the meter
will return to the normal operating mode.

Display Backlight

To turn the display backlight ON or OFF, press and hold the backlight

key for at least 1.5

seconds. The meter will beep when switching the backlight ON or OFF unless the beeper is
disabled as described in the Setup Mode section of this user guide.

4 SDL350-EU-EN-V1.1-9/11