SKC chek-mate 375 series, chek-mate 375-0550, chek-mate 375-0550N, chek-mate 375-00205N, chek-mate 375-00205 Operating Instructions Manual

chek-mate Flowmeter

Cat. No. 375 Series

Operating Instructions

863 Valley View Road, Eighty Four, PA 15330 USA • Tel: [phone] • www.skcinc.com

Inlet

Low battery

indicator

LCD screen

On/off

button

Introduction

Front View

Outlet

CalChek interface socket
(Cat. Nos. 375-0550N and

375-0550 only)

Battery

Figure 1. chek-mate Flowmeter Overview

Battery

compartment

cover

Back View

Description

The chek-mate® Flowmeter (Figure 1) is designed specifi cally for use with air sample pumps and is available in medium fl ow and
low fl ow models:

• Medium flow chek-mate Flowmeters with CalChek Cat. Nos. 375-0550N and 375-0550 have a flow measurement range of

0.5 to 5 L/min and provides CalChek capability. Volumetric accuracy is 1% of reading for 0.75 to 5 L/min and 2.5% of reading for

0.5 to 0.75 L/min. This model has a CalChek serial interface that enables direct communication with CalChek-ready pumps in the
chek-mate flow range for single-point (Single) and multiple-point (Full) automatic flow calibration.

• Low Flow chek-mate Flowmeters Cat. Nos. 375-00205N and 375-00205 have a flow measurement range of 20 to 500 ml/min.

Volumetric accuracy is 1% of reading for 50 to 500 ml/min and 2.5% of reading for 20 to 50 ml/min.

Checking Package Contents

See below to verify that you received all items associated with the Cat. No. ordered. If you are missing items, contact SKC
at 800-752-8472 (U.S. only) or 724-941-9701.

If You Ordered Cat. No. Your Package Should Contain

375-0550N Flowmeter with 9-volt alkaline battery and NIST-traceable calibration certifi cate

375-0550 Flowmeter with 9-volt alkaline battery and UKAS-traceable calibration certifi cate

375-00205N Flowmeter with 9-volt alkaline battery and NIST-traceable calibration certifi cate

375-00205 Flowmeter with 9-volt alkaline battery and UKAS-traceable calibration certifi cate

Required Equipment

; 1/4-inch ID tubing

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Form 39013 Rev 1905

Page 1 of 6

Getting Started

Notes and Cautions

• Allow chek-mate to equilibrate for at least 10 minutes after moving it from one temperature extreme to another before use.

• The chek-mate case is rated IP40, not as waterproof or splashproof; do not use it where water can enter the case.

• Ensure that fl uids do not enter either the inlet or outlet.

• Protect the chek-mate from direct exposure to sunlight to prevent it from heating the case.

• Avoid extended use of the chek-mate in areas with high levels of airborne particulates. If this cannot be avoided, use an external inlet fi lter with high
collection effi ciency (i.e., one that collects the majority of all dust particles) and low back pressure. SKC does not supply this.

• Use only the specifi ed disposable or rechargeable battery types.

• Ensure that discharged batteries are not left in the battery compartment for long periods to prevent damage caused by electrolyte leakage.

• There are no user-serviceable parts in the chek-mate fl owmeter. Opening the chekmate case will void the product warranty and could affect the
instrument calibration. An anti-tamper warning label is fi tted to the case to indicate that the case has been opened.

• Failure to follow these guidelines will void the warranty.

Turn On/Off

Allow the chek-mate to equilibrate for at least 10 minutes in the location where it will be used to ensure that it has stabilized to

ambient temperature.

To turn on the chek-mate, press the on/off bu on on the front. See Figure 1.

Read Battery Status on LCD

When the ba ery voltage drops below 8 volts as it nears the end of its life, LOW BATTERY will be displayed in the upper left corner
of the LCD (Figure 1). Replace the ba ery. See Maintenance.

When the battery voltage drops below 7 volts, the LOW BATTERY message displayed on the LCD will fl ash on and off and the chek-mate

will turn off automatically. If the chek-mate is turned on again with the battery still in this condition, the LCD will display bAtt LO ten
times and then turn off automatically.

Operation

Set/Calibrate Flow Rate

• Allow the chek-mate to equilibrate for at least 10 minutes after moving it from one temperature extreme to another.

• Protect the chek-mate from direct exposure to sunlight to prevent it from heating the case.

• Ensure that fl uids do not enter either the inlet or outlet.

• Avoid extended use of the chek-mate in areas with high levels of airborne particulates. See Notes and Cautions.

1. Turn on the fl owmeter by pressing the on/off bu on on the front. The LCD screen will
cycle through the startup messages, “On” followed by the upper limit of the fl owmeter
range (“5.0 L” for the medium fl ow model or “0.5 L” for the low fl ow model), and will
then indicate the current fl ow rate or “_ _ _ _” if there is no airfl ow or the fl ow rate is below
the minimum display value. Note: The minimum display value is dependent on the atmospheric

conditions, but at 68 F (20 C) and 1 atm (1013.25 mbar), the values are 5 ml/min for the low fl ow
chek-mate or 0.3 L/min for the medium fl ow chek-mate. Minimum display values will be higher

when the fl owmeter is used at higher altitudes and temperatures.

Note: The chek-mate does not zero the fl ow reading at startup, so it is also possible to turn it on with

the sample train already connected and airfl ow passing through the fl owmeter without aff ecting the
accuracy of the fl ow reading.

2. Connect the fl owmeter outlet to the inlet of the calibration train using a length of fl exible
1/4-inch ID tubing, and if required by the sampler, a calibration adapter. See Figure 2.

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Figure 2. Calibration Train

Form 39013 Rev 1905

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