The Smith Meter Model HR-LNC (High Resolution - Large Numeral Counter) Transmitter provides a digital pulse signal from a Large Numeral Counter for remote instrumentation. The output is either single-channel at 100 pulses per revolution of the LNC right-hand wheel, or dual-channel at 50 pulses per channel per revolution, with channel 1 leading channel 2 by 90°. The dual-channel pulse train can feed a Smith comparator totalizer (CDC-45 or CDC-41) that detects and alarms on a failed transmission line, a failed transmitter chip or line noise. Solid-state switching with a one-way clutch; factory- or field-mounted.
Key specifications
Models: HR-LNC-100 = 100 pulses per revolution, single channel; HR-LNC-50 = 50 pulses per channel per revolution, dual channel
Input power: 10 to 15 VDC; 65 mA max. single channel, 100 mA dual channel (6 VDC special operation for DFR indicator)
Output: Logic off 250 mV max.; logic on is a percentage of input voltage depending on receiver impedance (99% at 100 kΩ, 97% at 22 kΩ, 60% at 1 kΩ, 33% at 330 Ω)
On time / phasing: 50% ±10%; channel 1 leads channel 2 by 90° ±18°
Switching time: Rise 0.002 s max. at 1-10 mA; fall 0.0005 s max.
Input shaft speed / torque: 250 rpm max.; 2 oz-in (1 N·cm) max.
Temperature: Operating -40 to 180 °F (-40 to 82 °C); storage -67 to 257 °F (-55 to 125 °C)
Approval: UL listed for Class I, Group D, Division 1 hazardous locations
Wiring: #18 AWG shielded cable (3-conductor for HR-LNC-100, 4-conductor for HR-LNC-50), grounded at the instrument only; 2,000 ft (610 m) max. to the receiver; leads 48" long; 1/2"-14 NPT conduit
How to specify / order
The bulletin has no position-by-position model code. Per the ordering section, specify:
Model HR-LNC-100 (100 pulses per revolution) or HR-LNC-50 (50 pulses per channel per revolution)
Units of registration required
Pulse resolution required
Meter gearing ratio (for example 5:1 gallon, 1:1 barrel)
Factory-mounted or field-mounted
Bulletin notes: the logic-on output voltage is given only as a table of percentages, with no absolute value; the model table is headed "Closures per Revolution" although the HR-LNC is solid-state; SS01046 gives UL Class I, Group D only, while SS01100 lists Groups C and D plus CENELEC EExd IIA T6. Confirm approvals with the factory.
Pricing and lead time are quoted per configuration. Send the model number (or the details above) with your meter model and serial number to Flow Measurement Services for a quote. Specifications summarized from Smith Meter bulletin SS01046 Rev 0.0 (9/88); confirm current data with the factory before ordering.
Smith Meter (formerly FMC Technologies / TechnipFMC Measurement Solutions), now manufactured by Guidant. Flow Measurement Services supplies and services Smith Meter equipment.