Teledyne 4220, Installation And Operation Manual, Page: 16 / 198

4220 Flow Meter
Section 1 Introduction
1-2
• 674 Tipping Bucket Rain Gauge
• High Low Alarm Relay Box
Non-Isco Products
• IBM Personal Computer or compatible clone with Isco
Flowlink software
• Laptop Computer with Isco software
• YSI 600 Multi-Parameter Sonde
Optional Accessories
• 4200T Modem - Speech-capable, with connector and
cable
• D.O. (dissolved oxygen) and pH parameter probes
• Submerged probe Extension Cables (Vented), in lengths
of 25 and 50 feet. (Maximum distance between probe
and flow meter with extension cables is 75 feet.)
• Quick-Disconnect Box for Submerged Probe (Allows
installation of probe as far as 1000 feet from flow meter.)
• Isco Flowlink Software for data acquisition, storage, and
management
• Mounting rings and extensions for the submerged probe.
1.3 Operating Principles
When measuring flow rate, the 4220 is normally used with a
primary measuring device (weir or flume) or other open channel
flow arrangement where a known relationship exists between
level and flow rate. You can also use the 4220 to measure flow
using the
Manning equation . The level measuring device is a
submerged probe. The flow meter electronically converts the
level reading into a properly-scaled flow rate value. The flow
meter also provides standard or optional flow-related output
signals to be used for:
• Flow-proportional sampler pacing and enabling
• Transmitting level and flow data to an external device
on a serial communications loop
• Data transfer to a remote location through a modem
• Control of an external 4-20 mA device
• Data transfer by a laptop computer
The flow meter contains microprocessor-controlled circuitry to
calculate level and flow rates from the output produced by the
submerged probe, store user programming instructions, operate
the display and internal printer. An alphanumeric liquid crystal
display (LCD) shows current total flow, level, and flow rate infor-
mation. It also prompts you while you program the flow meter
during initial setup or subsequent program changes. An internal
printer provides a hard copy printout of the information com-
puted by the flow meter, plots level or flow rate, and generates
reports. Connectors for other equipment you can use with the
4220 Flow Meter are on the right side of the flow meter's case.