Atec 3112 User Manual

KNC Model 3112 Portable Live Pressure Calibration and Test System

Product Description

The Model 3112 Portable Live Pressure Calibration and Test System is a compact, completely self-contained
unit designed for calibrating and testing pressure gauges, transducers, pressure switches, and other
pressure-sensitive instruments up to 2,000 psi with an accuracy of ±0.5% of full scale. Two large, legible
gauges, reading from 0 to 100 psig and 0 to 2,000 psig respectively, and controlled by an automatic transfer
valve, permit precise stepless measurements over the entire range of the system. Other pressure ranges and
units of measure (e.g., kPa) are available upon request. For details, please see the Ordering Information
section below.

An internal nitrogen cylinder with a capacity of 90 cubic inches (7.1 std. cubic feet when charged at 2,250 psi
at 70°F), permits the Model 3112 Portable Live Pressure Calibration and Test System to be easily transported
to remote locations—no external gas or power sources are required. The cylinder can be charged using any
available high pressure nitrogen source, and is wire-wound for protection against impact. Additional safety
features include “blow-out back” master gauges to protect the operator from glass breakage in the event of a
malfunction, burst discs to guard against inadvertent overpressurization, and a relief valve designed to protect
the test item and master gauges from damage.

During setup, the Model 3112 Portable Live Pressure Calibration and Test System is first connected to the
item to be calibrated using a 5-foot-long braided test hose. The hose is terminated at both ends with 1/4"
female swivel AN fittings and doubles as a charging hose for the nitrogen cylinder.

To test an item, gas from the nitrogen cylinder is metered into the test circuit via a precision soft seat control
valve (see diagram below), and applies pressure simultaneously to the item undergoing calibration and the
master reference gauges. This enables the operator to easily perform comparative readings.

As the pressure is increased during testing, readings are transferred automatically from the low range (0 to
100 psig) gauge to the high range (0 to 2,000 psig) gauge. A second control valve is used for venting,
allowing precise downscale measurements to be performed. As the test pressure drops, the transfer valve
automatically switches from the high range gauge to the low range gauge.

A 65 to 250 VAC electrical tester is built into the Model 3112 Portable Live Pressure Calibration and Test
System for convenient pneumatic switch testing. The electrical tester is connected from the front panel of the
test system to the switch being tested using two 5-foot leads terminated with alligator clips. The presence of
electrical current is shown using a neon lamp. The lamp will illuminate to indicate that voltage is present;
when applied pressure trips the switch, the lamp will turn off.

All components of the Model 3112 Portable Live Pressure Calibration and Test System, including the test
hose, technical manuals, and other supplies, are housed in a weatherproof, compact, and rugged aluminum
carrying case with a locking hinged lid. A pressure relief valve built into the storage case protects the system
from internal gas leakage during storage.

Ordering Information

Standard versions of the Model 3112 Portable Live Pressure Calibration and Test System are equipped with a
0 to 100 psig low range master gauge and a 0 to 2,000 psig high range master gauge. NSN (National Stock
Number) 6685-821-0798 is applicable to this standard version.

The Model 3112 Portable Live Pressure Calibration and Test System may also be ordered with customer­specified measurement ranges for the master gauges. The minimum range available for the low range master
gauge is 0 to 15 psig. The maximum range for the high range master gauge is 0 to 3,000 psig. Other
modifications, such as metric scale units, are available upon special request. Please contact King Nutronics
Corporation for more information.