16 Model 7500 Instruction Manual
Teledyne Analytical Instruments
When a noise source is in the vicinity
Do not install the analyzer near power noise generating electric equipment (such as high frequency
furnace and electric welder). If the analyzer must be used near such equipment, a separate power line
should be used for avoiding noise. In case noise may enter from a relay, solenoid valve, etc. through
power supply, connect a varistor (such as ENA211-2 made by Fuji Electric) or spark killer (like S1201
made by OKAYA) to the noise source as shown below. If the varistor or spark killer is located away from
the noise source, no effect is obtainable. So, locate near the noise source.
(2) Analog output signal (AO): terminal block 1 (1 to 10, 15 to 20)
Output signal: 4 to 20 mADC or 0 to 1 VDC (selected when ordering)
Non-insulated output
Allowable load: 4 to 20 mADC, 550Ω or less
0 to 1 VDC, 100kΩ or less
• Analog output is provided from each terminal corresponding to the channel displayed in the
measurement screen.
Note: All of analog output signals for the instrument are not isolated. It is recommended to isolate
signals individually to prevent interference from unnecessary signals or to prevent external interference,
especially leading the cable of more than 30 meters or to outdoor.
(3) O2 sensor input: terminal block 2 (1 – 2)
Input signal:
External zirconia O2 analyzer: Zirconia O2 sensor signal (Teledyne output)
External O2 analyzer: 0 to 1 VDC (DC input resistor of 1MΩ or more)
• It is used when the external zirconia O2 analyzer or external O2 analyzer is specied as order.
• To connect to the output of the external Zirconia analyzer or external O2 analyzer prepared separately.
• In case of an external O2 analyzer, input a signal of 0 to 1 VDC with respect to O2 full scale of the
analyzer.
• In case of built-in O2 analyzer, do not use the terminals.
Note: O2 sensor input is not isolated. It is recommended to isolate input signal to prevent interference
from unnecessary signals or to prevent external interference. Zirconia O2 sensor should be installed at a
location that is as close to this instrument as possible.