Texas Instruments TR-525USW, 525, TR-525I User Manual

TEXAS ELECTRONICS, INC.

COMPLETE WEATHER STATION

USER’S MANUAL

5529 Redfield St. Dallas, TX 75235 P.O. Box 7225 Dallas, TX 75209

Phone [phone] Fax [phone] Toll Free [phone]

SERIES 525 RAINFALL SENSORS

DESCRIPTION

The sensor consists of a gold anodized aluminum collector funnel with a knife-edge that diverts the water to a
tipping bucket mechanism. The models TR-525I and TR-525USW are calibrated in inches (.01” per tip) and
model TR-525M is calibrated in millimeters (.1mm per tip). A magnet is attached to the tipping bucket, which,
as the bucket tips, actuates a magnetic switch. Thus, a momentary switch closure takes place with each tip of
the bucket. Connecting the sensor to an event counter on an electronic datalogger or display module will allow
record keeping of accumulated rainfall. If an analog signal representing rainfall accumulation is required,
Texas Electronics, Inc. manufactures a suitable conditioning circuit.

The spent water drains out of the bottom of the housing; hence, the sensor requires no attention or servicing of
any sort. It is completely automatic. The aluminum sensor housing is finished with a white baked enamel paint
to withstand years of exposure to the environment.

SPECIFICATIONS

Resolution: 0.01” or 0.1 mm
Accuracy:

English
Metric

Average Switch Closure Time: 135 ms
Maximum Bounce Settling Time: 0.75 ms
Maximum Switch Rating: 30 VDC @ 2 A, 115 VAC @ 1 A

Temperature Limits: +32°F to +125°F
Humidity Limits: 0 to 100%
Height: 10.125”
Weight: 2.5 pounds
Receiving Orifice Diameter:

Cable: 25 feet, 2-conductor
Installation: Consists of attaching the three sensor support legs to a firm

Maintenance:

Warranty: Three Years

1.0% at 1”/hr or less

1.0% at 10 mm/hr or less

6.060” (English)

9.664” (Metric)

8.000” USW (English)

platform or securing the side bracket to a stable vertical structure
such as the lower end of weather station mast. Sensor cable is then
connected to monitoring equipment.

Occasional cleaning of debris from filter screen may be required.

ORDERING INFORMATION

Model # Description

TR-525I Rain Gauge, 6.06” collector, English
(Please specify for calibration of 0.2 mm/tip)
TR-525USW Rain Gauge, 8.00” collector, English
TR-525M Rain Gauge, 25 mm collector, Metric

Optional Parts / Accessories

HOBO Event Datalogger and Software
MB-525 Pole Mounting Base
FC-525 Field Calibration Kit
BB-525 Bird Repellant
HT-525 Heater, 120 VAC
Cable Additional Cable

MODEL 525

TIPPING BUCKET RAIN GAUGE TRANSMITTER

INSTALLATION INSTRUCTIONS

A clear and unobstructed mounting location is necessary to obtain accurate rainfall readings.

This transmitter has provisions for mounting two ways, surface mounting and mast mounting. Surface
mounting is recommended where possible. The transmitter housing MUST be mounted in a LEVEL position
and in a location free from vibration. If mast mounted, make sure that the mast is properly guyed so that
vibration in high winds is kept to a minimum.

THE FOLLOWING IS VERY IMPORTANT:

After the final transmitter installation has been made, remove the top gold funnel portion of the transmitter and
observe the black tipping bucket. It should NOT (repeat NOT) be held in a dead center position by the
magnetic attraction of the bucket magnet and the hermetically sealed magnetic switch. Press either end of the
bucket down against the stop to be sure that it is not centered.

The transmitter to indicator connecting cable may be either shortened or lengthened as required.

The funnel and tipping bucket mechanism should be cleaned periodically. An accumulation of dirt, bugs, etc.
on the tipping bucket will adversely affect the calibration.

FIELD CALIBRATION

TR-525USW

Absolutely accurate calibration can be obtained only with laboratory equipment, but an approximate field check
can be easily made. The tipping bucket mechanism is a simple and highly reliable device. The transmitter must
be located in a clear area, away from trees, buildings, etc. It must also be mounted level. Accurate readings
will not be obtained unless the transmitter is mounted in a level position. The mechanism must be clean. Any
accumulation of foreign material, dust, etc. will alter the calibration of this unit. The transmitter must be
calibrated with the rate of flow of water through the tipping bucket mechanism under control. At least 36
seconds should be allowed to fill one side of the tipping bucket. This represents a maximum flow rate of on
inch of rain per hour. If the flow rate is increased, then the instrument will read low (if properly calibrated).
Decreasing the rate of flow will not materially affect the calibration. The reason for this is obvious if the
tipping bucket assembly is observed when the weight if this water starts to tip the bucket. Some time is
required for the bucket to tip (a few milliseconds). During the first 50% of this time, water flows into the empty
bucket. The amount of water flowing during the first 50% of the time is error, the faster the flow rate, the
greater the error. Now at flow rates of one inch per hour (100 bucket fillings) or less, the water actually drips
into the bucket rather than flowing. Under this condition, the bucket tips between drips, and no error water is
added to a full moving bucket.

TO CHECK CALIBRATION:

A field calibration kit is available from Texas Electronics, Inc. Model No. FC-525 is a kit that consists of a
holding tank, pre-measured beaker, two orifices, cleaning tools and instructions.

FIELD CALIBRATION

TR-525I & TR-525M

Absolutely accurate calibration can be obtained only with laboratory equipment, but an approximate field check
can be easily made. The tipping bucket mechanism is a simple and highly reliable device. The transmitter must
be located in a clear area, away from trees, buildings, etc. It must also be mounted level. Accurate readings
will not be obtained unless the transmitter is mounted in a level position. The mechanism must be clean. Any
accumulation of foreign material, dust, etc. will alter the calibration of this unit. The transmitter must be
calibrated with the rate of flow of water through the tipping bucket mechanism under control. At least 36
seconds should be allowed to fill one side of the tipping bucket. This represents a maximum flow rate of on
inch of rain per hour. If the flow rate is increased, then the instrument will read low (if properly calibrated).
Decreasing the rate of flow will not materially affect the calibration. The reason for this is obvious if the
tipping bucket assembly is observed in operation…with water falling into one side of the tipping bucket, there
comes a point when the weight of this water starts to tip the bucket. Some time is required for the bucket to tip
(a few milliseconds). During the first 50% of this tipping time, water continues to flow into the filled bucket;
the last 50% of this tipping time, water flows into the empty bucket. The amount of water flowing during the
first 50% of the time is error, the faster the flow rate the greater the error. Now at flow rates of one inch per
hour (100 bucket fillings) or less, the water actually drips into the bucket rather than flowing. Under this
condition, the bucket tips between drips, and no error water is added to a full moving bucket.

TO CHECK CALIBRATION:

A field calibration kit is available from Texas Electronics, Inc. Model No. FC-525 is a kit that consists of a
holding tank, pre-measured beaker, two orifices, cleaning tools and instructions.

04°F / 0.2°C

MODEL TTH-1315 TEMPERATURE HUMIDITY SENSOR

DESCRIPTION

The Texas Electronics, Inc. Model TTH-1315 Sensor utilized a Rotronics HygroClip S3 Humidity Temperature
Probe with interchangeable sensing elements that do not require calibration.

The unit is encased in a corrosive-resistant spun aluminum radiation shield that allows for wind aspiration and
protection from the sun's UV rays. The shield is finished in white baked-enamel to provide for virtual cosmetic
invisibility while reflecting much of the radiant heat from surrounding objects and the sun.

Overcurrent protection is provided in a NEMA 4X enclosure that is mounted to the angled mounting bracket on
the sensor. Tranzorbs are utilized to protect the sensor and signal conditioning units in an overcurrent situation.
With DC voltage applied to the sensor, the unit will return signal voltages that are linear to the range of the
instrument. Signal conditioning is applied to ensure proper voltages are returned and can be amplified or
modified to a current output to connect to any analog signal processing unit.

SPECIFICATIONS

Humidity Sensor: ROTRONIC HygromerÒ C94

(capacitive)
Temperature Sensor:
Sensor Protection: Wire Mesh filter (standard) /

Measuring Range: 0-100 % Relative Humidity

Operating Limits: Same as measuring range

RTD Pt100 Ohm, 1/3 DIN

foam filter (optional)

-40° to +140°F (-40° to +60°C)

Temperature

Accuracy at
73°F / 23°C:

Repeatability: Better than 0.5% RH and 0.1°C/

Analog output signals: 0…100% RH = 0…1V

+/- 1.5% RH and +/- 0.5°F /

0.3°C - standard calibration

+/- 1.0% RH and +/-

- special calibration (optional)

32.18°F

(minimum load >10k ohm)-

40…+140°F = 0…1V (-

40…+60°C)

Analog Signal Resolution 0.02%

RH and 0.1°F

Sampling Time: <0.7 sec
Maximum cable length: 5 m / 15 ft. for direct output

Up to 100 m / 325 ft. with signal

amplifier

Connection Type:

Protection grade: IP65 (probe to connector)
Supply voltage: 3.5 … 50VDC
Current consumption: <4 mA

Minimum excitation time: <4 sec

EMC compatibility (CE): EN-50081-2, EN-50082-2

Material: Polycarbonate, white
Dimensions:

Weight: 14 g / 0.5 oz.

Bayonet cap on mounting

connector

Length: 100 mm (3.94")

Diameter: 15 mm (0.59")

FEATURES & BENEFITS

• Combines Temperature and Humidity onto one sensing unit

• Rotronics HygroClip S3 has interchangeable sensing elements requiring no calibration

• Stacked plate construction of shelter provides natural ventilation

• Quick-Release mounting bracket allows for easy installation and maintenance

• Aluminum radiation shield is lightweight and extremely durable

• White baked-enamel finish reflects most radiant heat from sun and surrounding objects

INSTALLATION & MAINTENANCE

The radiation shield with sensing element can be pole or mast mounted. Whenever possible, sensors should be
installed at a height of 4 ft. (1.2 meters) or greater over earth or sod at least 100 ft. (30.48 meters) away from
any concrete or other hard-surfaced area and not closer to any other object than four times the height of the
object above the instrument shelter or remote sensors. Avoid roof installations if possible. If it is necessary to
roof-mount shelters and sensors, they should not be closer than 30 ft. (9.14 meters) to any large, vertical
reflecting surface (walls, etc.), exhaust fans, or cooling towers. Electronic remote sensors when roof-mounted
should be at least 9 ft. (2.74 meters) or greater above the roof surface. To minimize radiation effects from the
roof, they can also be mounted on a horizontal boom so that they will extend from the side of the building roof
or tower assembly.

ORDERING INFORMATION

Model # Description

TTH-1315 Temperature & Humidity Sensor
TTH-1315A Temperature & Humidity Sensor, 4-20 Ma

Optional Parts / Accessories

H50 Interior Humidity Sensing element only
Cable Additional Cable