Page 1 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Product Description
The model 921B and 922B Handheld Thermometer, with thermocouple inputs, are Intrinsically Safe instruments, which
may be used in Non-Hazardous or Hazardous (Classified) Locations.
Product Markings
The following information will be marked on a label affixed to the 921B or 922B product.
TEGAM Inc.
10 Tegam Way, Geneva OH 44041
Handheld Thermometer for Haz. Loc. Only as to Intrinsic Safety
0539
E506162
II 1 G
Ex ia IIB T4 Ga
Class I, Division 1, Group C and D, T4
Class I, Zone 0 AEx ia IIB T4 Ga
Zone 0 Ex ia IIB T4 Ga
DEMKO 19 ATEX 1970
IECEx UL 19.0010
-20 °C ≤ Ta ≤ +50 °C
NOTE: THIS IS AN AGENCY CONTROLLED DOCUMENT. NO CHANGES CAN BE MADE WITHOUT APPROVAL
OF THE NOTIFIED BODY.
Page 2 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Product Warnings
These warnings are provided as informational and are not marked on the product. Refer to the 921B Operation Manual
for further detail.
WARNING – EXPLOSION HAZARD – To reduce the ignition risk of a flammable or explosive atmosphere, batteries must
be changed in a location known to be non-hazardous.
ADVERTISSEMENT – RISQUE D’EXPLOSION - Afin de réduire le risque d’allumage dans une atmosphère inflammable
ou explosive, les batteries doivent être remplacées dans un endroit connu pour être non dangereux.
WARNING – EXPLOSION HAZARD – Batteries are part of the intrinsically safe system. Use only the specific battery
type, manufacturer, and manufacture’s part listed in the Manual. Use of other batteries could impair intrinsic safety.
Batteries may not be mixed.
ADVERTISSEMENT – RISQUE D’EXPLOSION - Les batteries font partie du système de sécurité intrinsèque. Utiliser
uniquement le type et le modèle spécifique de batterie et les pièces du fabricant mentionnées dans le manuel. L’utilisation
d’autres batteries pourrait affecter la sécurité intrinsèque.
WARNING – EXPLOSION HAZARD – Use only the probe types as listed in the manual. Use of other probe types could
impair intrinsic safety.
ADVERTISSEMENT – RISQUE D’EXPLOSION - Utiliser uniquement les types de sondes spécifiés dans le manuel.
L’utilisation d’autres types de sondes pourrait affecter la sécurité intrinsèque.
Product Operational Consideration
The following is provided as a user operational cautionary statement. It is not a requirement of the Standards nor is it
marked on the product. Refer to the 921B Operation Manual for further detail.
This instrument has a temperature classification of T4 or 135 °C maximum surface temperature. Consideration
should be given when using approved thermocouple probes in sensing environments exceeding this temperature class.
The probe sheath and/or tip can be at a temperature which may cause auto ignition in an explosive hazardous location.
Protective Components
F1 – Fuse, rated 80 mA; manufactured by Littlefuse, Inc., Part No. 451.080MRL.
R15 – Resistor, rated 8.25 – 8.75 Ω, 1%, 1/4 W, 1206 size, Thin or Thick Film.
VR1, VR2, VR3, VR4 – Diode, Zener, rated 5.6 V, 5%, 1 W, manufactured by Central Semiconductor, Part No.
CLL4734A. Alternate – Vishay Semiconductor, Part No. ZM4734A-GS08.
Safety Critical Component
L1 – Inductor, rated 10 µH, manufactured by Panasonic, Part No. ELLVGG100M.
Page 3 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Controlled Section Text Listing for the Operation Manual
Refer to the Operation Manual, TEGAM part number 921B-900, for the following controlled text content.
Compliance and Markings
E506162
TEGAM Inc.
10 Tegam Way
Geneva OH 44041
Handheld Thermometer for Hazardous Locations Only as to Intrinsic Safety
0539 II 1 G
Ex ia IIB T4 Ga
Class I, Division 1, Group C and D, T4
Class I, Zone 0 AEx ia IIB T4 Ga
Zone 0 Ex ia IIB T4 Ga
DEMKO 19 ATEX 1970
IECEx UL 19.0010
2.3 Agency Compliance and Safety Warnings
Ex Hazardous Safety Information
This instrument is intrinsically safe. WARNING: substitution of components may impair intrinsic safety. This
instrument complies with Agency Standards and is listed as:
• II 1 G Ex ia IIB T4 Ga
• Ex ia IIB T4 Ga
• Class I, Division 1, Group C and D, T4
• Class I, Zone 0 AEx ia IIB T4 Ga
• Zone 0 Ex ia IIB T4 Ga
This operation manual contains safety information and warnings that must be observed for safe operation under
the conditions described. Failure to comply with the information and instructions can have serious consequences.
Read this manual in its entirety before using the instrument.
Page 4 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
These warnings must be observed and are noted on the instrument’s battery door as shown.
WARNING
DO NOT OPEN BATTERY COMPARTMENT IN POTENTIALLY HAZARDOUS ENVIRONMENT, DISCONNECT
PROBES BEFORE OPENING.
ADVERTISSEMENT
NE OUVREZ PAS LE COMPARTIMENT DE LA PILE DANS UN ENVIRONNEMENT POTENTIELLEMENT
DANGEREUSE. DÉCONNECTEZ LES CORDONS D’ESSAI AVANT D’OUVRIR LE COMPARTIMENT Á PILE.
WARNING
Use only batteries listed in the manual.
ADVERTISSEMENT
Utilisez uniquement des piles dans le manuel d’instruction.
WARNING – EXPLOSION
HAZARD
To reduce the ignition risk of a flammable or explosive atmosphere, batteries
must be changed in a location known to be non-hazardous.
AVERTISSEMENT – RISQUE D’EXPLOSION
Afin de réduire le risque d’allumage dans une atmosphère inflammable ou
explosive, les batteries doivent être remplacées dans un endroit connu pour
être non dangereux.
WARNING – EXPLOSION
HAZARD
Batteries are part of the intrinsically safe system. Use only the specific battery
type, manufacturer, and manufacture’s part listed in the Operation Manual.
Use of other batteries could impair intrinsic safety. Batteries may not be
mixed.
AVERTISSEMENT – RISQUE D’EXPLOSION
Les batteries font partie du système de sécurité intrinsèque. Utiliser
uniquement le type et le modèle spécifique de batterie et les pièces du
fabricant mentionnées dans le manuel. L’utilisation d’autres batteries pourrait
affecter la sécurité intrinsèque.
WARNING – EXPLOSION
HAZARD
Use only the probe types as listed in the manual. Use of other probe types
could impair intrinsic safety.
AVERTISSEMENT – RISQUE D’EXPLOSION
Utiliser uniquement les types de sondes spécifiés dans le manuel. L’utilisation
d’autres types de sondes pourrait affecter la sécurité intrinsèque.
Page 5 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
2.5 Use of Certified Thermocouple Probes
Use only TEGAM IS9 Series of thermocouple probes or simple apparatus thermocouple leads, with either the
921B or 922B, in potentially hazardous locations. Use of any other probe or device invalidates the type
certification and may cause auto ignition in an explosive hazardous location.
Standard thermocouple leads, considered simple apparatus, which for example may have a welded bead end or
similar, can be used. Thermocouple extension wire can be used with either the TEGAM IS9 Series probes, or
standard thermocouples, up to a total length of 50 ft. (15.24 m).
The model 921B and 922B provides a maximum current of 0.551 A and power of 0.62 W for the thermal
evaluation of simple apparatus or extension wire.
2.7 Battery Installation and Replacement
Three (3) AA 1.5 V batteries are supplied with the instrument, but not installed. Read the following battery
replacement instructions before attempting to install or remove the batteries.
WARNING
Always change the product’s batteries outside Ex Hazardous areas.
CAUTION
Always turn the instrument off and disconnect any input connections before replacing the batteries. Re-
install the battery compartment cover before resuming use of the instrument.
CAUTION
The battery compartment is sealed with a rubber gasket. Use care to not damage the gasket when
removing or installing the battery compartment cover.
CAUTION
Remove the batteries when storing the instrument for an extended period or in a high temperature
environment to prevent battery leakage and possible damage to the instrument.
All measurement parameters may be reset to factory default if batteries are removed while the instrument is
powered on. Always turn the instrument off before changing batteries.
To install or replace batteries:
Required Tools: Phillips Head Screwdriver
1. Identify the battery compartment located on the back of the instrument (see Figure 1 below);
2. Remove the two (2) battery compartment retaining screws;
3. Remove the battery compartment cover;
4. If present, carefully remove old batteries being careful to not damage the battery contacts;
5. Use only Zinc-Manganese Dioxide or Alkaline-Manganese Dioxide AA cells that have been tested by a
nationally recognized laboratory to meet the requirements of UL 60079-11, Sixth Edition. Use of any other
battery will invalidate the Type Certificate and create a hazardous condition. The only batteries that TEGAM,
Inc. has secured such testing, which are approved for use in either a 921B or 922B, are listed on the Type
Certificate. They are:
• Energizer E91
• Duracell MN1500
Page 6 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
6. Observing proper polarity, install three (3) new, AA alkaline (IEC LR6, ANSI 15) batteries;
7. Re-install the battery cover and two (2) retaining screws;
8. At initial power on after battery replacement, allow approximately 30 seconds for instrument to stabilize.
Figure 1: Battery Installation
i
Retaining Screws
Battery
Compartment
Gasket
Page 7 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Typical Thermocouple IS9 Series Probe Connections with a 921B or 922B (Shown)
Page 8 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Typical Thermocouple (as Standard Apparatus) Wired Connections with a 921B or 922B (Shown)
Page 9 of 9
UL/cUL, ATEX/IECEx Control Drawing 921-400
TEGAM Inc.
10 Tegam Way • Geneva OH 44041
440-466-6100 • FAX 440-466-6110
Revision Record
Revision
Date
ECO#
Summary of Changes
C
9/29/2020
6544
Change to new format.
D
8/30/2021
6843
Change allowable wire length as will be noted in Sect. 2.5 of
the manual.
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