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Float-Type Instruments Float Gage - Model 8850 Water Level Recorders Shaft Encoders Float Gage & Shaft Encoder Sensor Accessories Float Tape & Beaded Cable Accessories Recorder Accessories

Water Level Recorders

US Type A-71 US Type F

US Type A-71 Water Level Recorder

The US Type A-71 Water Level Recorder provides continuous, unattended recording - with high accuracy regardless of range. The Type A-71 has been improved and perfected over the years and today it is still the world-wide standard in quality and reliability for river hydrography and other installations where long term operation is required.

A Type A-71 Recorder uses a strip chart and pen marker to provide a permanent on-site record of water level fluctuations. Both metric and English models are available. The recorder is precision-made to respond to 3 mm water level change at 1:5 scale (or 0.01 ft. at 1:6 scale) using a 254 mm/10 inch float. The float is used with either a beaded float line or a float tape (graduated in meters, decimeters, centimeters or feet, tenths, hundredths). A clock drive controls the movement of the strip chart at a constant speed. The pen marker moves laterally across the chart and reverses direction at each margin to provide an unlimited recording range.

The recorder stands on a three-legged cast metal base, and has an ABS plastic cover with a full face gasket and a clear viewing port. Safety features to prevent accidental record loss include an automatic friction roller engaging knob and a safety pawl attachment.

Strip charts are printed on high quality paper to minimize humidity effects. Several days of record are normally visible with recorder in operation. The 25 cm wide A-25 chart is for metric measurement and the 10 inch wide A-10 chart, for English measurement. A disposable cartridge pen is provided as standard equipment.

Time scales are designated by the number of inches of chart utilized in one day. The chart speed specified most frequently is 2.4 inches (6.1 cm) per day at which speed the chart will last about a year. Standard time scales are easily interchanged in the field. With the QMT drive this is done by switch selection - with other drives by substituting gears.

Two chart drives are available. Timer and time scale gears can be easily changed in the field.

• Quartz Multispeed Timer (QMT) - The most frequently specified, the QMT uses a 6 volt battery. It can be used with solar cell battery charger for 5 year minimum operation. Time scale gears need never be changed again since seven switch-selectable scales are available.
• Negator Spring Drive with Chelsea Clock - for time scales up to 12.2 cm/4.8 inches per day. This chart drive uses a large spring which slowly unwinds from one drum onto another, driving the instrument's chart for 4 1/2 months or on special order for 6 months. The Chelsea clock regulates the rate at which the spring unwinds and thus the speed of the chart.

Gage Scales: The ratio between the chart record and water-level changes is known as Gage Scale, e.g. a 1:5 Gage Scale means that the record will be 1/5 actual size (Standard English Scales are multiples of the ratio 1:12). Instruments may be converted in field from English to metric system, and vice versa.

Also required for operation and sold separately are one of each of the following:

• Float Pulley
• Beaded line or float tape
• Float
• Counterweight
• End Hooks

 

Basic Instrument Specification:

Float operated water-level recorder; rectangular strip chart 25 cm/10 inches by 22.9m/25 yards; gage scale standard for 1:5 metric/1:6 English; cartridge type pen with spare cartridge, quartz multispeed timer (QMT); plastic cover with viewing port; cast aluminum base with three leveling screws.

802-010      A-71 Recorder - English      45 lbs.

802-020      A-71 Recorder - Metric      45 lbs.

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US Type F - Water Level Recorder

The US Type F Water Level Recorder is an inexpensive, accurate versatile recorder for general-purpose recording including:

• Stream gaging
• Irrigation
• Sewerage
• Water supply
• Ground water studies

The Type F Water Level Recorder is an instrument for permanently recording varying levels of any liquid surface. Among other uses, flow data may be obtained by use with weirs, Parshall flumes or other rated measuring structures in which heights, or differences in heights, are an index of flow.

The rise and fall of the float with changing water levels turns the drum proportionately, as the clock-controlled pen moves across the chart at a constant speed. The resulting graph shows the water level against a record of time. The range in stage is limited only by the length of the float line and float size, since the chart drum may make any number of revolutions.

The time period of recording may vary from 12 hours to 32 days, (depending upon chart, gearing, and type of clock drive). Charts are available with English or metric divisions.

A balanced, ball-bearing mounted chart drum responds to 0.01 ft. (3 mm) change at 1:1 scale, using a 5 in. float. The instrument is actually sensitive to 0.002 foot (0.6 mm) and can record to such a degree of accuracy if a large enough float is employed.

Features:

• Accurate quartz multispeed timer (QMT) eliminates need for time scale gear changes. Battery operated time scales corresponding to 32, 16, 8, 4, 2, 1 and 1/2 days of chart operation.
• Compact, portable, self-contained power
• Quick, easy chart changing
• Easy field conversion to vary recording ratio
• Unlimited range in stage
• Charts - with English or Metric scales
• The Recording Pen - The Recorder is supplied with a cartridge style nylon tip pen
• Choice of stainless steel beaded float line or direct reading graduated tape
• Scow float eliminates float well (optional)

Also required for operation and sold separately are one of each of the following:

• Float pulley
• Beaded line or float tape
• Float
• Counterweight
• End hooks

Gage Scales are required for use and are included in Basic Recorder price. The relation between the rotation of the float pulley and the chart drum is set by gearing. Thus changes in the gearing or the pulley circumference affect the ratio between the chart record and water level changes. This ratio is known as gage scale. To make a field change from any scale listed (except 1:20) to another requires only the substitution of a pair of gears. The 1:20 scales are obtained by installing the 750 mm or 36" circumference ring on float pulley of a recorder geared for 1:10.

Basic recorder system includes recorder, chart, cartridge type pen with spare cartridge, cast aluminum base and metal cover. Also included is Quartz Multi-Speed Timer equipped with a seven switch selectable time scale for 0.5, 1, 2, 4, 8, 16, and 32 days.

802-030      Type F Recorder - English      25 lbs.

802-040      Type F Recorder - Metric      25 lbs.

 

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