hmd-sm manual 20101208 - logika techlogikatech.com/.../2011/07/hmd-sm-manual-20101208.pdf · mm...

Model HMD-SM Scanning Hot Metal Detector

Operator’s Manual

Version 12-2010

Logika Technologies Inc. Model HMD-SM Operator’s Manual Rev. 12-2010

Web: www.logikatech.com Phone: 905-829-5841 Fax: 905-829-8787 Email: [email protected]

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Contents

1. Introduction ...................................................................................................................... 2

2. Description ....................................................................................................................... 2

2.1 Model Nomenclature .................................................................................................. 2

2.2 Specifications .............................................................................................................. 3

2.3 Operating Principle ...................................................................................................... 3

2.4 Automatic Threshold Level Adjustment ....................................................................... 6

2.5 Other Features ............................................................................................................ 6

3. Location and Mounting ..................................................................................................... 6

3.1 Sensor Location ........................................................................................................... 6

3.2 Sensor Mounting ......................................................................................................... 7

4. Utility Connections ........................................................................................................... 8

4.1 Electrical Connections ................................................................................................. 8

4.2 Plumbing Connection ................................................................................................ 11

4.3 Air Purge Connection ................................................................................................. 11

5. Operation ....................................................................................................................... 13

5.1 Controls ..................................................................................................................... 13

5.2 Automatic Threshold Level Description..................................................................... 14

5.3 Remote Threshold Sensitivity Control ........................................................................ 14

5.4 Test Function ............................................................................................................. 15

5.5 Troubleshooting ........................................................................................................ 15

6. Maintenance .................................................................................................................. 17

6.1 Regular Maintenance................................................................................................ 17

6.2 Returns of the HMD-SM ............................................................................................ 17

7. Accessories- Hot Metal Simulation Test Bar .................................................................... 18

8. HMD-SM Enclosure Dimensions ..................................................................................... 19



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1. Introduction

The Logika Technologies scanning mode hot metal detector, Model HMD-SM, is

designed for automation of steel, aluminum and other metal mill production lines. It

includes a rugged enclosure protecting state-of-the-art electronics and will withstand

the harsh ambient conditions present in heavy industrial environments. The HMD-SM is

used to detect hot metal of various temperatures, shapes and sizes in wire, bar, strip,

thin plate, thick plate, billet and slab production facilities.

The HMD-SM is a scanning mode hot metal detector, enabling it to detect hot metal

Anywhere across the entire width of a production line. The scanning capability and

advanced sensor detector allow the sensor to be installed remotely from the hot metal

target, further protecting the electronics and extending the life of the sensor.

The sensor’s control panel is equipped with a dual position sensitivity switch which gives

a single sensor the capability of detecting hot metal at any temperature above 250oC

(480oF).

2. Description

2.1 Model Nomenclature

Record your Hot Metal Detector’s complete Model Number here:

HMD - ___________ - __________

Base Model Scan angle Power Input

HMD 10: 10 Degree 110: 110 VAC

30: 30 Degree 220: 220 VAC

50: 50 Degree 24: 24 VDC

Serial Number _________________



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2.2 Specifications

Operating temp 0˚C to +50˚C (32˚F to 120˚F). With water cooling: 120˚C (250˚F)

Detect Range 0.2-8m

LED Indicators Green = power on, Red = target detect, Orange= Detector signal

saturation or dirty lens, Off=Alarm

Output Relay NO/NC 250VAC @ 10A, closing: 7.5ms, opening: 3ms Push-Pull type output max 100mA @24VDC Diagnostic outputs: control, alarm, signal amplitude

Power Input 24 VDC, 110VAC, 220VAC @ 30VA

Cable 9 x 20Ga plus (shielded) 7 x 24Ga Insulation 20MΩ, 500VDC, ≥500˚C (930˚F)

Housing Hermetically sealed cast aluminum enclosure rated IP66, includes cooling

water connections and air purge.

Size Enclosure; 406 mm L x 112 mm D x 280 mm H (with mounting bracket) (16”L x 4.4d” x 11”h)

Weight 8kg

Min Target Temp 250oC (480oF)

Scanning Angle 10˚, 30˚, 50˚

Water Cooling 25˚C, 4 bars pressure (60 psi), 1-2L/min (0.26 to 0.52 USG),

¼” flexible tube

Air Purging 50 to 200 g/cm2

(0.7 to 2.8 psi), 4-16L/min (0.14 to 0.56 cfm)

¼” compression fitting

2.3 Operating Principle

Detector- The HMD-SM uses a Lead Sulfide (PbS) photocell, which is characterized by a very

strong signal output for the range of infrared energy emitted by steel, compared with other

detector materials. The high signal-to-noise ratio that results from this superior detector

virtually eliminates detection errors. Figure 2.1 shows the spectral response of various types of

photocells with the infrared spectral output of hot steel.



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Figure 2.1:

Graph of Spectral Response of Various Types of Photocells vs. Infrared Output of Steel

Scanning System- The HMD-SM uses a scanning optical bench that enables hot metal detection

across a broad angle of detection. The optical field is scanned using a rotating drum of multiple

mirror facets that reflect the energy from the hot metal target in the scanning field to the PbS

detector. This process is shown in Figure 2.2. At the detector the infrared energy is converted

to an electronic signal, which is then processed by the electronic circuitry and changed to a

logic signal for control purposes.

Figure 2.2: HMD-SM Scanning System



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Vertical Scanning Angle- The HMD-SM is manufactured with one of three vertical field angles

10, 30 and 50 degrees, selectable at the time of sensor purchase. This enables the sensor to

cover the entire process area but not scan beyond the process line where interfering sources of

infrared energy may be present. Figure 2.3 shows vertical scanning field size versus hot metal

target distance from the sensor for several scenarios.

Figure 2.3: Size of Vertical Scanning Field vs. Distance From Hot Metal Target

Vertical Scanning Field Example- For a hot metal target located 4 meters (13’) from the front of

the HMD-SM sensor with a vertical scanning angle set at 30o, the vertical scanning field is 2.10

meters or 84 inches.

Horizontal Scanning Angle- A manually adjusted shutter at the front of the sensor is used to

determine the horizontal measurement angle from 1 degree to 3 degrees (see Section 3.1

“Mounting Distance”). For example, the scanning width (at a shutter width angle of 1 degree)

at 4 meters (13 feet) distance, the scanning width is 8 mm. A positive output signal will result if

any portion of the hot metal is within the 8 mm scanning field.



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2.4 Automatic Threshold Level Adjustment

The HMD-SM includes an Automatic Threshold Level Adjustment to automatically decrease the

detector signal when hot metal is detected to prevent detector signal saturation. The user

adjusts the base gain level via a potentiometer mounted on the sensor’s control panel (please

see Sections 5.2 and 5.3 for additional details on use of this feature). The detector will return to

the base signal level upon exit of the hot metal from the scanning detection field. This feature

makes the sensor more stable and significantly reduces detection errors caused by target black

spots or varying surface temperature and interference from water vapor and oxide scale.

2.5 Other Features

� Upon exit of the hot metal from the scanning detection field, the sensor’s output signal changes

quickly to decrease control lag time.

� Because the HMD-SM’s PbS detector has a superior signal-to-noise ratio, the sensor is able to

detect low temperature and low emissivity targets even in the presence of background infrared

interference and roller heat radiation.

� The Pulsed Signal Zoom Mode automatically reduces the temperature drift of the HMD-SM

detector.

3. Location and Mounting

3.1 Sensor Location

The installation distance between the HMD-SM Sensor and hot metal target should be selected

to allow full coverage of the process line, protect the sensor from excessive process heat, and

be close enough to give the detector sufficient infrared energy to reliably detect the target.

� Mounting Distance- Select an approximate sensor mounting distance from the hot metal target

based on the following table. Consult the table below on the size of the detection scanning

field to help determine scanning angle setting (10o, 30

o, or 50

o) and to be sure that the distance

that the sensor is mounted from the target will cover the entire process area. The vertical

scanning field of the sensor should be oriented across the width of the process line for best

coverage.

Target Sensor Distance Target Sensor Distance

Wire, 5 mm-12 mm 0.2 m to 3.0 m Strip Steel 0.6m to 2m

Bar, 10 mm-40 mm 0.2 m to 4.0 m Thin Plate 1.0m to 6.0m

Square Billet 0.5 m to 6.0 m Thick Plate 1.0m to 8.0m

Large Billet >2.0 m Slab >2.0m



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� Interference- Background infrared radiation sources, such as other hot processes behind the

target and reflected sunlight, should be reduced or eliminated:

1. Select the appropriate scanning angle when the sensor is ordered so that the sensor does not

“over-scan” the target.

2. Gradually reduce the sensitivity adjustment on the HMD-SM’s control panel until the

background interference is not detected in the absence of the target metal. See the

“Operation” chapter of this manual for additional details.

3. If necessary, install a background radiation screen between the target and the interference

source to block its infrared energy from reaching the detector.

� Other Installation Considerations

1. Place the sensor to reduce interfering infrared sources and choose a detection field that

minimizes the presence of dirt, smoke and water vapor or other infrared absorbing chemicals.

2. Only part of the target needs to be in the sensor’s field of view to create a hot metal output

signal.

3.2 Sensor Mounting

� Mounting Bracket- The HMD-SM has an adjustable mounting foot designed to allow easy

rotation through horizontal and vertical axes. The sensor is fixed to the support with a single 18

mm bolt through the HMD-SM’s base mounting stand. The support must be sufficiently rigid to

absorb any excessive site vibrations that could affect the precision output of the detector.

� Air, Cooling Water Fittings- The HMD-SM has a water-cooling jacket and an air-purged hood for

protection of the window glass. These sensors can thus be used in harsh environments with

high temperatures, steam, dust and smoke. Please see Section 4.2 Plumbing Connection and

Section 4.3 Air-Purge Connection for further details on installing these protections for your

sensor.

� High Heat Option- For installation where ambient temperatures exceed 250oC (480

oF), it is

recommended that the HMD-FOC Fiber Optical Hot Metal detector be ordered.

� Caution- For installation in environments that may include excessive water vapor or smoke, it is

recommended that additional ventilation such as air curtains or fans be used to clear the area

so the sensor can “see” the hot metal target.



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4. Utility Connections

4.1 Electrical Connections

� Electrical Overview- All electrical connections (power and signal) to the HMD-SM are made via

a 15-pin connector with ground. The sensor is supplied with a mating connector at the back of

its enclosure and a standard 2-meter cable with the quick-connect assembly mating to the

sensor and ferrules for the junction box connections. Other cable lengths are available from

Logika Technologies upon request.

� Cable Specification-

• Multi-lead cables of 9 x 20 gauge (9 x 0.6 mm²) and shielded 7 x 24 gauge (7 x O.34 mm²)

• Teflon insulation for high temperature applications.

• Outer metallic braid for mechanical protection.

• Overall diameter of 9 mm.

• Minimum bending radius of 30 mm.

• Each lead is color-coded.

� Junction Box Wiring- Please see Figure 4.1 for the sensor wiring diagram. The supplied cable

should be connected directly to the terminals of a junction box. All cables must be shielded all

the way to the console with the shield connected to ground to eliminate electrical noise, which

may trigger false detection. Any unused output wires must have insulation protection or be

connected to free terminals in the junction box.

� Power Connections- Power Input (please specify power input at time of order).

• White/Red, White/Brown 115VAC/60Hz

• White/Black, White/Brown 220VAC/50Hz

• White/Red, White/Black DC24V

� Voltage Output- Outputs available after hot metal detection.

• Transistor Static Output: Push-pull output maximum current 100 mA, output voltage 0 VDC or

24 VDC

• Output Response time:

o HMD-SM-10 (10 degree scanning field): 1ms



� Relay Output- Single-pole double throw contacts, contact capacity rating is 250VAC/10A, relay

operating time = 7.5 ms, relay release time = 3 ms.

Note: Static output and Relay output are isolated, which means two types of outputs may be

used, separately or both at the same time.



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� Sensor Diagnostics Outputs- Relay and voltage signals to indicate sensor conditions.

1. Control Output (See “Sensor Wiring Diagram”, Figure 4.1, Terminal 2A): Normally 24V, 0VDC

diagnostic Alarm indicates dust or vapor interference on glass, target temperature drop, or

signal saturation. Signal is referenced to Return, Terminal 3B.

2. Alarm Output (See “Sensor Wiring Diagram” Figure 4.1, Terminal 4C): Normally 24V, 0VDC

diagnostic alarm indicates no power input, scan motor abnormal, or inside sensor case

temperature is higher than 55oC (130

oF). . Signal is referenced to Return, Terminal 3B.

3. Signal Amplitude Output (See “Sensor Wiring Diagram”, Figure 4.1, Terminal 3C): Signal

amplitude is an analog voltage signal, 0-13.5 VDC, proportional to the photocell output. This

signal may indicate that the sensor’s protective glass lens requires cleaning or that the detector

sensitivity needs to be increased. Signal amplitude strength is influenced by:

• Installation position and location of sensor in process

• Size of the target

• Temperature of the target

• Distance between the sensor and the target

• Vapor in the field

• Dust on the Lens

• Sensitivity Adjustment Setting



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Figure 4.1: Sensor Wiring Diagram



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4.2 Plumbing Connection

� Description- Water cooling is required when the ambient temperature at the sensor’s location

is higher than 50oC (120

oF). Temperatures above this level require protection for the

electronics. A standard cooling water fitting is available at the sensor enclosure and copper

heat exchanger tubing is embedded in the sensor housing to facilitate efficient heat removal

from the sensor using circulating cooling water.

� Cooling Water Requirements

• Clean industrial water

• Maximum water inlet temperature of 25oC (75

oF).

• Maximum water pressure of 4 bars (60 PSI)

• Water flow rate of 1 to 2 L/min (0.35 to 0.56 ft3/min)

� Connection- Use ¼” flexible tube to connect the plant’s cool water supply to the sensor cooling

water fitting and secure with a hose clamp. Use Figure 4.2, Ambient Temperature vs. Water

Flow Rate Graph, to determine the cooling water flow rate for the ambient conditions around

the sensor.

Figure 4.2: Ambient Temperature vs. Water Flow Rate

4.3 Air Purge Connection

� Description- Compressed plant air can be used to prevent dust and vapor from entering the

protective shroud around the lens of the sensor. Using plant air with the sensor will reduce

lens cleaning maintenance and prolong sensor life where dust or corrosive vapors are present.



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� Compressed Air Requirements

• Must be clean, dry air free of contaminants. Poor purge air quality will lead to dirty glass which

may decrease sensor performance and increase sensor maintenance. Air filtration prior to the

sensor purge inlet fitting is recommended for purge air of questionable quality.

• Air Pressure range of 50 to 200 g/cm2

(0.7 to 2.8 psi)

• Air Flow rate of 4 to 16 L/Min (0.14 to 0.56 ft/min)

� Connection- Connect the plant purge air pipe to the air purge fitting on the sensor’s lens shroud

using a ¼” compression fitting. The purge air flows out of the sensor shroud and dissipates into

the ambient environment.



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5. Operation

5.1 Controls

The HMD-SM Sensor’s Control Panel is located under the protective cover plate on the back of

the sensor. The following functions are available at the Control Panel. See Figure 5.1

L = LED Process Status Indicator Light-

Green: No target detected, standby mode.

Red: Target acquired.

Orange: Detector signal saturation or dirty lens.

Off: Alarm

T = Sensor Test Button- activates visible laser positioning beam for easy sensor aiming.

PN, PH = Threshold Level Adjustment Potentiometers- adjust sensitivity of the detector within

each range of sensitivity, N (normal) and H (high).

S = Sensitivity Range Switch

Figure 5.1: HMD-SM Operator Panel



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5.2 Automatic Threshold Level Description

� Definition- The HMD-SM includes an Automatic Threshold Level Adjustment. The sensor’s

circuitry will automatically decrease the detector signal when hot metal enters the target area

to prevent detector signal saturation. The user adjusts the Threshold Level Potentiometers at

installation to determine the base detector signal according to the application requirements.

� Sensitivity- As the potentiometer setting increases from 1 to 7 (rotate clockwise), the detector

sensitivity (gain) increases. This enables the user to prevent interfering background radiation

from resulting in false positives at the sensor output. The lower the potentiometer setting, the

hotter the target should be and the more interfering background radiation will be eliminated.

� Automatic Threshold Level Adjustment Procedure

1. Put hot process metal or the Logika Technologies Hot Metal Simulation Test Bar in the HMD-

SM’s target field.

2. Normal (N) Applications- For steel applications with a target temperature hotter than 400oC

(750oF), set the sensitivity switch (S) toward “N” on the control panel and the “N” threshold

level potentiometer to 3 (middle position). Adjust the potentiometer setting up or down until

the LED light changes from green to red. This is your lowest threshold setting for this

application. It is recommended that, once the detection threshold is found, move the

sensitivity potentiometer adjustment one unit higher (clockwise) as an operating threshold

level.

3. High (H) Applications- For steel applications with a target temperature less than 400oC (750

oF)

and as low as 250oC (480

oF), set the sensitivity switch (S) toward “H” on the control panel and

the “H” threshold level potentiometer to 3 (middle position). Adjust the potentiometer setting

until the LED light changes from green to red. This is your lowest threshold setting for this

application. It is recommended that, once the detection threshold is found, move the

sensitivity potentiometer adjustment one unit higher (clockwise) as an operating threshold

level.

4. If the LED does not change from green to red with hot metal in the target area, be sure that the

sensor is targeted properly and that the target metal is at process temperature over 250 oC

(480 oF), then adjust the width between the two light shield boards (Horizontal Scanning Angle

adjustment, see Section 2.2.) This will increase the amount of infrared energy to the detector.

Go back to the above steps to reset the sensitivity potentiometers.

Caution-

• Decreasing the threshold and increasing the sensitivity may result in false positive detections.

• The sensor should be aimed at the gaps between rollers to avoid false positives caused by

latent roller heat.

5.3 Remote Threshold Sensitivity Control

The adjustment of the threshold level can also be carried out remotely.

� Install a user-supplied 4.7K potentiometer wired between Terminal leads A3 and B3 in the

control room of steel mill.



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� When this remote adjustment capability is used then the “N” and “H” potentiometers on the

LT_HSM Sensor’s Control Panel must be set to 1 (fully counterclockwise).

� Jumpering the wiring leads from terminals B2/B3 enables “High (H) Applications” adjustments

from the control room.

� Leaving the wiring leads from terminals B2/B3 unjumpered enables “Normal (N) Applications”

adjustments from the control room.

5.4 Test Function

To test the electrical integrity of the HMD-SM sensor, follow the steps below:

� Connect power to the sensor.

� Press and hold the “TEST” button on the control panel when hot metal is not in the target field

of the sensor. The LED on the Control Panel should turn from green to red. The test button

simulates a positive signal from the detector. It will also actuate the sensor’s relay output

(close the alarm circuit) to test the control function in your system as long as the test button is

pressed.

� Release the test button to return to normal operation and end the test function.

5.5 Troubleshooting

� Missed Target- If the LED does not turn red or the process alarm (Terminal 5) does not actuate

when a hot metal target is present, there are two possibilities:

1. The Horizontal Scanning Angle Shutter located at the front of the sensor is closed. Manually

adjust the shutter to allow the target’s infrared energy to reach the detector.

2. The threshold potentiometer is set too low. Go to Threshold Sensitivity Adjustment, Section

5.3, and recalibrate the sensitivity adjustment.

� False Positive Target Detected-

1. The threshold potentiometer is set too high. Go to Threshold Sensitivity Adjustment, Section

5.3, and recalibrate the sensitivity adjustment.

2. If step 1 does not correct false positives, check for background sources of radiation such as

reflected sunlight or hot processes behind the target line. Correct these conditions as

necessary by adjusting the sensor aim or by blocking the interfering radiation source.

� Diagnostic Signal Output Detected- Check the diagnostic signals available and their status

indication (see Section 4.1 Sensor Diagnostic Outputs for details). Correct fault conditions as

necessary. See additional notes below:

• Control Output terminals 2A3B No Power- Check that the sensor wiring connections are

correct, that the connections are secure and tight and that the power supply is proper and

normal.



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• Alarm Output terminals 4C/3B normally will output a signal of 24VDC. If the output is 0V

following a detected error, the following situation may occur:

1. If the housing temperature is over 55oC (130

oF), then water cooling must be used (see

section 4.2). If water cooling is already in use, then check the water’s inlet temperature and

for flow restrictions to the unit.

2. Scanning Error (motor error or circuit error) means that the rotating drum motor may have

failed. Please contact Logika Technologies for resolution.



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6. Maintenance

6.1 Regular Maintenance

� Diagnostics- Normally, the HMD-SM does not require maintenance at a fixed period. Regular

attention to the following will ensure steady operation of the sensor:

� Lens Cleaning- Routinely check the HMD-SM sensor’s glass for dust or oil residue. Open the

lens shield board at the front of the sensor by unscrewing the fastening hardware on the shield

and clean the glass with alcohol and lens paper or soft cloth.

� Detector- Monitor the Signal Amplitude Output at electrical Terminal 3 (see Section 4.1) for the

general condition of the HMD-SM sensor’s detector and optical system.

� Adjustments- The threshold level sensitivity (see Section 5.2) and the light shield board may

require occasional adjustment. The screw at the front of the sensor allows adjustment of the

light shield boards.

6.2 Returns of the HMD-SM

� Contact us with the Serial Number of your sensor before you return our product. If we are

unable to solve the problem by phone or email, we will then provide you with a return

authorization number.

� Do not return the HMD-SM without an authorization number.

� If the product is out of warranty, we will provide a repair estimate and then complete the

repairs after your approval.



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7. Accessories- Hot Metal Simulation Test Bar

� In order to facilitate the installation, use and maintenance of HMD-SM hot metal detector and

other infrared sensors, Logika has developed a hot metal simulation test bar, Model TP-1. This

process simulation tool uses an AC power supply of 110/220V with the maximum power of 500

W. The power output can be adjusted by the potentiometer on the test bar to simulate

different process temperatures.

� When using the TP-1 test bar, please note the following:

• The power supply should be supplied with a ground.

• The test bar is constructed of sensitive electronic components. Use care when handling the

unit.

• This test bar should be used for a maximum of one (1) hour on a constant basis. When not

being used, please switch off the test lamp or darken it. When it is used again, turn on or

lighten the test lamp.

• When the lamp tube is damaged, return it to Logika Technologies for repair or replace the

infrared lamp source at your site. The lamp tube used is an iodine tungsten lamp tube of

110/220 V, 500 W.

Figure 7.1: Hot Metal Simulation Test Bar Drawing



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8. HMD-SM Enclosure Dimensions

Figure 8.1: HMD-SM Enclosure and Mounting Bracket Dimensions

hmd-sm manual 20101208 - logika techlogikatech.com/.../2011/07/hmd-sm-manual-20101208.pdf · mm...

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