PrecisionTM Instruction Manual
If a stable air supply is not available, an air pressure regulator and reducer valve should be placed in the feed line. The
Precision Air Pressure Regulator, Catalog #74803, may be ordered as an accessory item if such a regulator is required.
Thermometer Installation: Insert a thermometer (ASTM 3C or 3F, Temperature range 5 to + 400C or 20 to 760F) in the
thermometer well provided in the center of the bath. The thermometer is not provided.
Pyrometer Connections: The Indicating and Controlling Pyrometer, Catalog No. 74802, is a recommended accessory for
the Gum Bath.
Complete instructions are furnished with each Pyrometer, including wiring diagram and parts list, and should be referred
to for all pertinent information.
See Gum Bath Schematic Wiring Diagrams for Indicating and Controlling Pyrometer Wire Connections.
Operation
Preparation of the apparatus, preparation of the sample, test procedure, calculations and reporting, and appropriate
tables are supplied in the ASTM Method.
ASTM test methods can be obtained from:
American Society for Testing Materials
1916 Race Street
Philadelphia, Pennsylvania 19103
SAFETY CONSIDERATIONS AND WARNINGS:
The following guidelines are presented to supplement the existing safety rules enforced by your company:
1.
Safety glasses should be worn by the operator and by anyone in the vicinity who could be struck by glass fragments
caused by flask breakage or by splashing from handling liquid samples.
2.
It is recommended that a fire extinguisher of Halon 1211 or C02 (at least a 5-lb. tank size) be placed
conveniently in reach of the operator of the unit to protect against sample fires which might accidentally occur during
testing.
3.
Service or circuit testing should be attempted only by a qualified person who has been trained with regard to the
potential danger of working with live electrical circuitry.
WARNING: Disconnect the unit from the power source whenever replacing electrical
components.
4.
Insulated gloves should be used when handling hot components.
Explanation of Switches:
The two switches, located on the front of the bath, control the power to the Controlling Pyrometer and the Auxiliary Strip
Heaters.
The switch marked "AUX" is in series with the relay contacts and the 2 strip heaters, (660W each). When this switch is
engaged, the strip heaters are turned "On" or "Off" through a set of relay contacts, the relay being energized by the
Controlling Pyrometer.
The switch marked "INT" supplies power to the Controlling Pyrometer, which in turn controls the relay and the 3 ring
heaters (300W, 400W, and 880W each).
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