ELECTRICAL SAFETY TEST INSTRUMENTS
ESI-200: PORTABLE ELECTRICAL SAFETY TESTER
Model ESI-200 is a simple to use, cost-effective instrument designed to perform the required standard electrical tests on all line-operated equipment according to NFPA, AAMI and UL standards. To perform the tests, the Electrical Safety Inspector uses only two toggle switches and two push-buttons. Many essential safety tests can be made with the Inspector:
Line Voltage and Receptacle Polarity: By depressing a momentary push-button, the line voltage is digitally displayed on an LCD panel meter. Neon lights indicate the correct receptacle wiring.
Two-Terminal Resistance Tests: By touching the exposed metal surface of the equipment under test (EUT) with the 6-Ft coiled cord/probe, the grounding quality is measured to the nearest ±0.01W. A red LED indicates that the unit is in the resistance measurement mode.
Four-Terminal Resistance Measurement: For very low resistance grounding tests, Model ESI-200 uses the supplied 6-Ft coil cord and the ground reference lead. As the current source and the sense wire are connected inside the test probe at the tip, the Inspector measures resistance by a true four-terminal method.
Data Output Recording: The unit’s 0-2 volt data output in conjunction with a printer documents the test data. An optional RS-232 interface with PC-based software is also available.
Equipment Leakages: With the EUT plugged into the Inspector’s test receptacle, the NORMAL, REVERSE and OPEN GROUND true RMS leakage current is digitally displayed on the LCD panel meter to the nearest ±1mA, up to 20mA. A red LED indicates the unit is in the current leakage measurement mode. In the case of a ground fault the HOT warning light turns on.
External Leakages: Currents with respect to or above ground can be measured in patient leads, probes, endoscopes, scanners, EEG connections, etc. Leakage current measurements above ground are made by floating the Inspector’s receptacle ground reference.
Voltage Differential Tests: Ground voltage differential measurements from 1.0mV to 20V in patient areas are made by setting the unit in the LEAKAGE position and referencing the test lead to a receptacle ground. This test is also recommended to verify the receptacle line voltage drop between neutral and ground. The recommended level is less than six volts.
BET-300AD: BIOMEDICAL ELECTRICAL SAFETY TESTER
OHMIC Instruments’ Model BET-300AD performs electrical safety tests for compliance to AAMI, UL-544 and NFPA-99 standards. This Biomedical Electrical Test Set was engineered and field-tested by hospital and biomedical engineers for ease of operation, ruggedness and portability. The unit performs safety tests on electrical equipment and instrumentation including grounded and isolated power supplies (Model BET-300ADL). A digital auto-ranging readout and function indicator lights quickly indicate fault and electrical risk conditions. The meter simulates probable fault conditions such as loss of equipment ground and reverse power wiring.
Functions include leakage current, voltage above or reference to
ground and resistance tests with respect to ground. In order to
minimize any shock hazard to the operator and limit high frequency
interference from external sources the test set is earth grounded.
Current leakage tests are performed utilizing the AAMI standard
load which provides a flat response for frequencies from DC to 1KHz
and -20dB per decade greater than 1KHz. The equipment under test
is simply plugged into one of two front panel test receptacles for
either the grounding resistance/poor insulation or current leakage
tests. An external probe connected to a coiled cordset is supplied
for external chassis leakage and resistance tests. Five color coded
jacks enable the simultaneous leakage testing of patient leads.
Each lead adapter is supplied with an individual switch. BET-300ADs
are equipped with a built in 10μA reference current source and
a 0.25W resistance standard for verifying the operation and calibration
of the unit. The optional model BET-300ADL indicates fault currents
in isolated systems. BET-300ADs provide the standard electrical
safety testing required for maintenance and biomedical departments
in health care facilities. Each unit is supplied with a certificate
of calibration and backed by OHMIC’s engineers.