Ice*Meister™ Model 9734
INDUSTRIAL ICE DETECTING SENSOR SYSTEM

DESCRIPTION

Ice*Meister™ Model 9734 industrial ice detecting sensor system is a general purpose go/no-go ice-and-precipitation sensor that passively removes standing water from the sensor optics by force of gravity. It detects rime ice, snow, frost and condensation by optical opacity, and clear ice and rain by optical refraction. There are no moving parts.

As shipped from the factory, Model 9734 is highly sensitive; it detects the first 0.001" of ice or better. As part of the installation process, you  "de-sensitize" the system for your specific application by (1st ) selecting one of three icing-level relay outputs,
(2nd ) adjusting the laser drive, and (3rd ) adjusting the amplifier gain. These three cascaded adjustments provide an extremely wide range of system performance, appropriate to each different kind of application.

Model 9734 operates as a elemental go/no-go gauge, so users can be alerted to take appropriate action in the event of ice or other precipitation, including rain. Although it provides a very wide range of go/no-go thresholds, it has  no specified accuracy, and is not intended to be used as an analog measuring instrument.

Being optical in nature, it detects individual raindrops in real time -- without having to accumulate water.

There are four major components of the system:

(A) The sensor head is contained in a rugged 3" x 2" x 1" ABS plastic box with a 3mm optical probe extending from one side.  The sensor head assembly incorporates an optional heating element to de-ice the sensor optics if required.  Model 9734 senses the moment when falling rain has turned to ice. 

(B) The sensor head is fixed to one of  two types of mounting plates such that it can be installed either open to the sky (type O), or such that the sensor probe can be installed in a refrigerator (type R), with the 3mm sensor probe positioned between any two particular condenser-coil fins.

(C) A heavy duty cable connects the sensor head / mounting plate assembly to the user interface board and host system. A light duty cable is available for applications not requiring a sensor de-ice feature.

(D) Model 9733 user interface board can be located up to 220 feet away from the sensor head. Twenty feet of cable is provided standard, and an optional 100' extension cord can be added. A second 100' extension cord can also be added in series for a total of 220' separation between sensor head and user-interface board

The Model 9733 user interface board can be enclosed in an optional NEMA 4X box  with a clear plastic cover for display of the system status LEDs. Electrical connection to the systems' host computer or data logger is via isolated relay contacts, so the  possibility of system ground loops is minimized.

APPLICATIONS

Ice*Meister™ optical sensors are predictable, adaptable, robust and effective. They sense all forms of opaque and clear ice and precipitation in any ground-based application, including motor vehicles. They are for use in a variety of applications ...

• Agricultural, commercial and residential  sprinkler controls,
• Vehicle dispatch offices
                  
• Windpower farms
• Industrial freezers
• Tethered blimps
• Radio broadcast towers
• Suspension bridges
• Roadway ice warnings signs
• Meteorological stations
• Vehicle windshield wiper controls
• Weather stations
• Wireless networking
• Grocery stores, supermarkets
• Household refrigerator defrost controls
• Oil & Gas installations
• Ice-indicating municipal  traffic signals
• Household indoor-outdoor weather stations
           
• Heliports and helipads at hospitals, police stations, offshore oil rigs, etc.
• Water level sensing

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FEATURES

• DC operation
• No MHz clock
• Lightweight
• Low cost parts
• Low cost labor
• Nothing to break
• Low cost fabrication
• 3mm diameter probe
• Extends 3/8 inch from face
• No loose parts
• One-piece solid acrylic construction
• Sensitive to the first 0.001" of ice, or better.
• Acrylic structure embeds easily into host enclosure
• Four elements fused together:  laser - fiber - body - receiver

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BENEFITS

• Prevents irrigation and lawn sprinkling during rainfall;  prevents sprinkling over ice.
• Simple
• Robust
• Lightweight
• Adaptable
• More sensitive than hydroscopic discs
• No moving parts
• Real time operation
• Instant sprinkler shutoff
• Instant reset after rain stops

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Table 1 - Output Data Format

ICING STATE	LEDs DISPLAY	RELAY CONTACTS
		no ice	ice alert	more ice	saturation ice	rain
no ice 1000	1 green  LED	closed 1	open 0	open 0	open 0	x
ice alert 0100	1 red  LED	open 0	closed 1	open 0	open 0	open 0
more ice 0110	2 red LEDs	open 0	closed 1	closed 1	open 0	open 0
saturation 0111	3 red LEDs	open 0	closed 1	closed 1	closed 1	open 0
rain 1	orange LED ON	1	0	0	0	closed 1
no rain 0	orange LED OFF	0	0	0	0	open 0

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(A) SENSOR HEAD ASSEMBLY

SENSOR HEAD PROBE

SENSOR HEAD BOX

(B) MOUNTING BRACKETS

Two types of plastic mounting brackets are available:

Type "O" is for open mounting  in open air, such as on heliports at hospitals, police stations, oil rigs, etc, windpower farms, radio towers, meteorological towers, suspension bridges, tethered blimps,  roadway overpasses, golf courses, agricultural watering controls. Install with sensor box up, and plate level to the horizon. Dimensions: 11" x 4" x0.5"

Type "R" is a refrigerator nose for installation in industrial refrigerators.  The front end of the bracket is cut away,  so the sensor probe can be positioned between any two evaporator fins, where ice would displace air. Dimensions: 7.5" x 4" x 0.5"

Diagonally slotted holes are provided for attaching U-bolts to handrails, cantilevers, etc. Plate can be drilled or sawed as required. Mounting brackets are made of special UV-robust marine grade polymer sheet, designed for tropical marine use as deck boxes and other fittings on commercial fishing vessels. Contact factory for specs. Do not disturb the countersunk stainless steel hardware on bottom. Operating temperature range -40℃ to +90℃

(C) CABLE ASSEMBLIES

24 AWG 7 strand copper shield & drain wire operating temp range: -40℃ to +90℃ jacket material: thermal plastic elastomer jacket wall: 0.30 inch nominal finished cable OD : 0.375 inch nominal Insulation wall: 0.012 inch nominal insulation type:   HDPE High Density Polyethylene shielding type: aluminum polyester tape maximum voltage: 300 Volts heavy duty connectors use a cable support before the bracket secure the cable at every opportunity use messenger cables whenever feasible total cable lengths: 20', 120', 220' >220' consult factory	Heavy duty cable
	Heavy duty connecters
	Lightweight cable

INTERFACE BOARD

Model 9733 User interface board is radio silent, has no MHz clock.  Board weighs 1 oz,  measures 1.5" x 4.75", operates to -40 ℃, can be enclosed in a NEMA 4X box.

REAL-TIME RAIN SENSING SPRINKLER CONTROL

Model 9734 sensor element is useful as part of an optical rain detector for sprinklers and general irrigation control.  With it agricultural, commercial and residential  sprinkler controls can prevent costly overwatering during natural rainfall by shutting off the sprinkler's main valve, and restoring normal operation as soon as the rain stops.

Ordinary sprinkler controls rely on a spongy material to expand when it gets wet, but this delays shutoff of the water valve for a substantial amount of time after it begins to rain; Thus, system sprinkler heads can often be seen spraying valuable water during periods of natural rain. 

The 9733 interface board's reaction to each individual raindrop falling on the sensor element face is to trigger a monostable multivibrator (1-shot), beginning with the very first raindrop to hit the face.  This produces a 10-second output pulse which activates the RAIN relay and display LED for 10 seconds. 

If subsequent raindrops continue to fall on the sensor face, the 10-second timeout is continually reset, and so the RAIN signal remains asserted TRUE for the entire duration of natural rainfall. 

When the last raindrop falls and no others follow it, the 10-second timer times out and allows the water control valve to operate normally again.

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WATER SAVER

Because there is no required accumulation of rainwater after the onset of rain, this feature completely eliminates all time delay before the sprinklers shut off.  Because there is no drying out period required after the rain stops, 9734  completely eliminates any time delay before the sprinkler system returns to normal again.

Used in conjunction with ICE ALERT, the RAIN signal can prevent sprinkling water on already-frozen surfaces.

Model 9734-OEM  digital go/no-go sensor elements offer precise control for... 

• irrigation sprinkler on-or-off
• vehicle windshield wipers on-or-off
• HVAC defroster coils on-or-off
• helipad ice melting heat exchangers on-or-off
• water level sensor on-or-off
• ice-warning intersection traffic signals on-or-off
• household indoor-outdoor thermometer ice-alert icons on-or-off

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CONTACT US

For more information about the new Ice*Meister Model 9734, please fill out the form below and click Send. Thank you.

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