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EM-V Series electromagnet specifications

APPLIED FIELD STRENGTH WITH OPTIONAL HIGH-FIELD 2 IN POLE FACE—EMP-HF (±1%)
ExactGAP™ setting	Air gap	EM-4V maximum field	EM-7V maximum field
Index 1	7.5 mm (0.30 in)	27.6 kOe (2.76 T)	32.2 kOe (3.22 T)
Index 2	12 mm (0.47 in)	25.2 kOe (2.52 T)	29.8 kOe (2.98 T)
Index 3	20 mm (0.79 in)	20.3 kOe (2.03 T)	26.0 kOe (2.60 T)
Index 4	25 mm (0.98 in)	17.2 kOe (1.72 T)	23.8 kOe (2.38 T)
Index 5	28 mm (1.10 in)	15.5 kOe (1.55 T)	22.7 kOe (2.27 T)
Index 6	50 mm (1.97 in)	9.1 kOe (0.91 T)	16.0 kOe (1.60 T)

APPLIED FIELD STRENGTH WITH STANDARD 2 IN POLE FACE (±1%)
ExactGAP™ setting	Air gap	EM-4V maximum field	EM-7V maximum field
Index 1	7.5 mm (0.30 in)	26.1 kOe (2.61 T)	30.5 kOe (3.05 T)
Index 2	12 mm (0.47 in)	23.7 kOe (2.37 T)	28.3 kOe (2.83 T)
Index 3	20 mm (0.79 in)	19.6 kOe (1.96 T)	24.7 kOe (2.47 T)
Index 4	25 mm (0.98 in)	16.9 kOe (1.69 T)	22.8 kOe (2.28 T)
Index 5	28 mm (1.10 in)	15.4 kOe (1.54 T)	21.7 kOe (2.17 T)
Index 6	50 mm (1.97 in)	9.1 kOe (0.91 T)	15.4 kOe (1.54 T)

*APPLIED FIELD STRENGTH WITH STANDARD 4 IN POLE FACE (±1%)**
ExactGAP™ setting	Air gap	EM-4V maximum field	EM-7V maximum field
Index 1	57.5 mm (2.26 in)	7.9 kOe (0.79 T)	13.5 kOe (1.35 T)
Index 2	62 mm (2.44 in)	7.3 kOe (0.73 T)	12.8 kOe (1.28 T)
Index 3	70 mm (2.76 in)	6.5 kOe (0.65 T)	11.7 kOe (1.17 T)
Index 4	75 mm (2.95 in)	6.1 kOe (0.61 T)	11.0 kOe (1.10 T)
Index 5	78 mm (3.07 in)	5.9 kOe (0.59 T)	10.7 kOe (1.07 T)
Index 6	100 mm (3.94 in)	4.6 kOe (0.46 T)	8.6 kOe (0.86 T)
*Achieved by removing high or standard 4 in to 2 in pole caps

*APPLIED FIELD STRENGTH WITH STANDARD 7 IN POLE FACE (±1%)**
ExactGAP™ setting	Air gap	EM-7V maximum field
Index 1	146.5 mm (5.77 in)	6.0 kOe (0.60 T)
Index 2	151 mm (5.94 in)	5.9 kOe (0.59 T)
Index 3	159 mm (6.26 in)	5.6 kOe (0.56 T)
Index 4	164 mm (6.46 in)	5.4 kOe (0.54 T)
Index 5	Not recommended for this pole cap configuration
Index 6	Not recommended for this pole cap configuration
*Achieved by removing standard 7 in to 4 in pole caps; only valid for EM-7V magnet

EM-4V typical field uniformity

Magnet configuration		Uniformity over 1 cm³	1% cylindrical volume
Pole cap mm (in)	Air gap mm (in)	Uniformity over 1 cm³	Diameter mm (in)	Length mm (in)
51 (2.0)	13 (0.5)	±0.16%	36 (1.4)	13 (0.5)
51 (2.0)	25 (1.0)	±0.35%	18 (0.7)	25 (1.0)
102 (4.0)	25 (1.0)	±0.05%	64 (2.5)	25 (1.0)
102 (4.0)	51 (2.0)	±0.15%	18 (0.7)	51 (2.0)

EM-7V typical field uniformity

Magnet configuration		Uniformity over 1 cm³	1% cylindrical volume
Pole cap mm (in)	Air gap mm (in)	Uniformity over 1 cm³	Diameter mm (in)	Length mm (in)
51 (2.0)	13 (0.5)	±0.11%	36 (1.4)	13 (0.5)
51 (2.0)	25 (1.0)	±0.33%	10 (0.4)	25 (1.0)
102 (4.0)	25 (1.0)	±0.03%	66 (2.6)	25 (1.0)
102 (4.0)	51 (2.0)	±0.08%	23 (0.9)	51 (2.0)

NOTE: The third column gives uniformity over one cubic centimeter volume centered in the magnet gap. The last two columns give the cylindrical volume within which the magnetic field deviates by less than 1% from the central field. The cylindrical volume is coaxial with the magnet poles and centered in the gap.

General specifications

		EM-4V	EM-7V
Air gaps	With no pole caps	57.5, 62, 70, 75, 78, and 100 mm
	With 2 in pole caps	7.5, 12, 20, 25, 28, and 50 mm
Coil resistance, nominal		0.25 Ω per coil (0.5 Ω total wired in series)	1.00 Ω per coil (0.5 Ω total wired in parallel)
Coil resistance, cold		0.23 Ω per coil (0.46 Ω total wired in series)	0.92 Ω per coil (0.46 Ω total wired in parallel)
Coil resistance, maximum		0.27 Ω per coil (0.54 Ω total wired in series)	1.08 Ω per coil (0.54 Ω total wired in parallel)
Integrated pole diameter		100 mm (4 in)	178 mm (7 in)
Available pole cap diameters		50 mm (2 in)	100 mm (4 in) and 50 mm (2 in)
Cooling water		Tap water or closed cooling system
Water flow rate		7.6 L/min (2 gal/min)	11.4 L/min (3 gal/min)
Pressure drop		200 kPa (30 psi)	220 kPa (32 psi)
Water chiller cooling capacity		2.5 kW (8,530 BTU/h)	5.0 kW (17,060 BTU/h)
Water inlet temperature		15 °C to 25 °C (59 °F to 77 °F)
Coil over temperature limit		45 °C (113 °F)
Coil spacing, nominal		121 mm (4.75 in)	178 mm (7 in)
Coil size-width, nominal		121 mm (4.75 in)	132 mm (5.2 in)
Coil size-diameter, nominal		311 mm (12.25 in)	445 mm (17.5 in)
Current (maximum continuous operating)		±70 A	±135 A
Voltage, nominal		±35 V (approximately 38 V at maximum coil temperature)	±70 V (approximately 38 V at maximum coil temperature)
Continuous input power, nominal		2.5 kVA (2.65 kVA at max temperature)	9.45 kVA (10.125 kVA at max temperature)
Suggested power supply		Lake Shore Model 643	Lake Shore Model 648
		Size
Height		77 cm (30.3 in)	52.7 cm (20.8 in)
Width		78.7 cm (31 in)	78.7 cm (31 in)
Depth		88.9 cm (35 in)	88.9 cm (35 in)
Weight of yoke and coils, no rolling base or pedestal, approximate		227 kg (500 lb)	567 kg (1250 lb)
Weight		201.9 kg (445 lb)	635 kg (1400 lb)
Shipping weight		215.5 kg (475 lb)	660 kg (1500 lb)
Shipping dimensions		0.97 m × 0.58 m × 0.56 m (38 in × 23 in × 22 in)	0.86 m × 1.22 m × 1.19 m (34 in × 48 in × 47 in)