Extech Instruments 406800 User manual

User's Guide
Differential Pressure Manometer
Model 406800

406800 V2.1 11/062
Introduction
Congratulations on your purchase of the Extech 406800 Differential Pressure Manometer.
This device measures Gauge/Differential Pressure from 0 to 138.3 inH2O (inches of water).
It features 11 selectable units of measure: inH2O, psi, bar, mbar, kPa, inHg, mmHg, oz/in2,
ftH2O, cmH2O, kg/cm2. Additional features include: Data Hold, Auto Power Off disabled,
and an RS-232 for capturing readings to a PC using optional software (407752). Careful
use of this meter will provide years of reliable service.
Specifications
Function Range Resolution
inH2O ±138.3inH2O 0.1inH2O
psi ±5.000psi 0.001psi
bar ±0.344bar 0.001bar
mbar ±344.7mbar 0.1mbar
kPa ±34.47kPa 0.01kPa
inHg ±10.18inHg 0.01inHg
mmHg ±258.5mmHg 0.1mmHg
ozin2±80.00oz/in20.01oz/in2
ftH2O ±11.53ftH2O 0.01ftH2O
cmH2O ±350.1cmH2O 0.1cmH2O
kgcm2±0.351kg/cm2 0.001kg/cm2
Display Dual LCD
Accuracy ±0.3%FS
Repeatability ±0.2% to 0.5% FS
Linearity/Hysteresis ±0.3%FS
Combined Accuracy ±1.1%FS (+5 to -4psi) (-4 to -5psi unspecified)
Connectors Two metal 4.8mm ports for flexible tubing
Maximum Pressure 20psi
Response Time 0.5 seconds typical
Compatibility Air or Non-Corrosive Gases
Low Battery Indicator Yes
Overrange Indicator Err.1
Underrange Indicator Err.2
Compensated Temperature Range 32 to 122ºF (0 to 50ºC)
Operating Conditions 32 to 122ºF (0 to 50ºC); < 80% RH non-condensing
Storage Conditions -4 to 140ºF (-20 to 60ºC); <80% RH non-condensing
Power Supply 1 x 9V battery
Dimensions / Weight 7.1 x 2.8 x 1.1” (182 x 72 x 30mm); 7.7 oz. (220g)
Note: Exceeding maximum pressure will cause sensor damage.

406800 V2.1 11/063
Meter Description
1. 4.8mm input connectors
2. Dual LCD Display
3. On/Off
4. Data Hold and Zero Adjust
5. Unit of Measure
6. Backlight
7. Differential Function and Zero Offset
8. AC adaptor input
9. Min/Max Record
10. RS-232 input
Note: The battery compartment is located
on the bottom of the instrument
Display Description
1. Hold Function
2. Differential Mode
3. Primary Data screen
4. Relative Time Clock
5. Pressure Unit indicator
6. Low Battery indicator
7. Max/Min
8. Record Mode
1
2
3
4
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7
8
9
10

406800 V2.1 11/064
Operation
Power
Press the ON/OFF button to turn power on or off. The meter will perform a short self-test
when turned on. The meter defaults to the setting used during the last operation.
Zero Adjust and Offset
Before use and without fittings attached to the meter, press the HOLD button for more than 2
seconds to zero the meter. The meter will reset and display “o o o o” from right to left. “0.0”
will now be displayed.
If it is desired to offset the meter’s display, press the DIF button while taking a measurement.
Subsequent readings will be the difference between the current measurement and the
measurement that was on the display when the DIF button was pressed.
Data Hold
Press the HOLD button momentarily to freeze the displayed reading. The 'HOLD' icon will
appear on the upper left-hand side of the display. Press the HOLD button again to return to
normal operation.
Record
The MAX/MIN mode allows the user to view only the highest (MAX) or lowest (MIN) readings
with relative time stamp.
1. Press the REC button once and “REC” appears on the display (All other functions
are locked out except for Power & Backlight). The relative time clock also appears
in the secondary display and starts counting.
2. Press the REC button again and “MAX” appears on the display. The display is now
showing the maximum pressure and relative time that it was recorded.
3. Press the REC button again to display the minimum “MIN” reading with the relative
time.
4. Press the REC button again to continue recording min/max measurements.
5. To exit the MIN/MAX mode, press the REC button for 3 seconds to return to normal
operation.
Backlight Display
Press the key to turn on the backlight. It will remain on for 30 seconds.
Automatic Power Off
The meter will automatically shut off after 20 minutes to conserve battery life. To disable Auto
Power Off, hold down the HOLD button and turn the meter on. An “n” will appear in the
display indicating that Auto Power Off mode is disabled. The meter will return to normal
operation when it is turned off.
Unit
Press the Unit button momentarily and the meter will cycle through the 11 available units of
measure as indicated by the cursor on the bottom of the display.

406800 V2.1 11/065
RS-232 PC Communications Interface
The meter has a built-in RS-232 serial port for use with the optional PC Interface Data
Acquisition Software/Hardware kit (407752).
Error Codes
An error message will appear on the display if the meter fails an internal diagnostic test.
Note: Error messages E10L and E2UL will not display on the LCD. They will be transmitted
to the PC via the RS-232 cable.
1. Err.1: Pressure value is over the range.
2. Err.2: Pressure is below the range.
3. Err.3: DIF function, the differential pressure value is over range.
4. Err.4: Zero function, disconnect tubing or repair/replacement necessary.
5. E10L: RS-232 error, Pressure value is over the range.
6. E2UL: RS-232 error, Pressure is below the range.
Maintenance
Cleaning and storage
1. The meter should be cleaned with a damp cloth and mild detergent when necessary.
Do not use solvents or abrasives.
2. Store the meter in an area with moderate temperature and humidity (refer to the
operating and storage range in the specifications chart earlier in this manual).
Battery Replacement
When the battery power falls low, “BAT” will appear on the LCD. Replace the 9V battery by
removing the Phillips screw on the battery compartment door and accessing the battery
compartment. Ensure that the compartment cover is securely fastened when finished.
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also provides
NIST certification for most products. Call the Customer Service Department for information on
calibration services available for this product. Extech recommends that annual calibrations be
performed to verify meter performance and accuracy.

Support line [phone]
Technical support: Extension 200; E-mail: [e-mail]
Repair & Returns: Extension 210; E-mail: [e-mail]
Product specifications subject to change without notice
For the latest version of this User’s Guide, Software updates, and other
up-to-the-minute product information, visit our website: www.extech.com
Warranty
EXTECH INSTRUMENTS CORPORATION warrants the basic instrument to be free of
defects in parts and workmanship for one year from date of shipment (a six month limited
warranty applies on sensors and cables). If it should become necessary to return the
instrument for service during or beyond the warranty period, contact the Customer Service
Department at [phone] EXTENSION 210 for authorization or visit www.extech.com for
more information. A Return Authorization (RA) number must be issued before any
product is returned to Extech. The sender is responsible for shipping charges, freight,
insurance and proper packaging to prevent damage in transit. This warranty does not apply
to defects resulting from action of the user such as misuse, improper wiring, operation
outside of specification, improper maintenance or repair, or unauthorized modification. Extech
specifically disclaims any implied warranties or merchantability or fitness for a specific
purpose and will not be liable for any direct, indirect, incidental or consequential damages.
Extech's total liability is limited to repair or replacement of the product. The warranty set forth
above is inclusive and no other warranty, whether written or oral, is expressed or implied.
Copyright ©2006 Extech Instruments Corporation.
All rights reserved including the right of reproduction in whole or in part in any form.
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Email: [e-mail]
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