Starting at $1,745.00

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  • Non-contact measurement of level or open channel flow
  • ±0.25% of Range or 2mm (0.08in) accuracy
  • Repeatability and Linearity: ±0.1%
  • Simple 5-key calibration
  • Isolated 4-20mA output
  • Programmable control relays
  • NEMA4X (IP66) polycarbonate enclosure
    • Watertight & dust tight with shatterproof cover
  • False echo rejection
  • 2 programmable control relays (upgradeable to 6)
  • Electrical surge protection
  • Intrinsically safe sensor option
  • Plug and play relay and data logger options

What's in the Box

  • Level sensor
  • Coaxial sensor cable
  • PC software utilities disk
  • Installation and operation manual
  • NIST certificate

The Greyline Instruments SLT 5.0 level and flow monitor is a versatile instrument designed to continuously measure, display, transmit and control liquid level in storage tanks and pumping stations, or to monitor and totalize open channel flow through any flume or weir. The non-contact ultrasonic sensor mounts above the liquid being measured so it will not obstruct the flow nor be prone to fouling.

The SLT 5.0 is easy to set up and operate. Use the built-in 5-button keypad/menu system to input the calibration parameters and the SLT 5.0 will quickly calculate the volume in horizontal round tanks, or flow rate (and total) through any flume or weir. The standard PVC and Teflon sensor is rated for measurement ranges up to 32ft. The SLT 5.0 provides an accuracy up to 0.25% of Range or 2mm (0.08in) whichever is greater.

The SLT 5.0 has an isolated 4-20mA output which can transmit flow data to remote chart recorders or displays. The two control relays (upgradeable to six) are programmable for level/flow alarm, and flow proportionate pulse (for samplers, chlorinators or remote totalizers). An Intrinsic Safety Barrier is optional for sensor and cable installation in hazardous rated locations. The separate, watertight electronics/display enclosure is mounted at a convenient location within 500ft (150m) of the sensor


Greyline Instruments XC Sensor Cable
RG62AU coaxial cable available in lengths up to 500 feet


Greyline Instruments PZ15-LP Level Sensor
Low profile, non-contacting ultrasonic level sensor ideal for confined spaces and small flumes
Greyline Instruments PZ15 Level Sensor
Non-contacting ultrasonic level sensor is small enough for very small flumes and powerful enough for really large applications.
Greyline Instruments PZ34 Level Sensor
Non-contact, PVC level sensor with 32 foot range with liquids
Greyline Instruments PZ32T Level Sensor
Non-contact, PVC and Teflon level sensor with 32 foot range with liquids
Greyline Instruments PZ32TE Level Sensor
Non-contact, Teflon level sensor with 32 foot range in liquids


Please consider these optional accessories.

Greyline Instruments JB2X Sensor Cable Junction Box
NEMA4X/IP66 polycarbonate junction box for extending sensor cable lengths
Greyline Instruments CHS Spare Electronics Set
Spare set electronics with mounting chassis (standard features)


This product can be used in the following applications:

Application Notes

Here's how some of our customers used this product.

Manhole Flow Monitoring

The Background: Our customer is a municipal utility that needs to monitor flow through an open channel accessed through a manhole.

The Problem: The flow though the channel is intermittent drainage and, as such, the application cannot insure the full pipe standard that standard inline flow meters require.

The Solution: We recommended the Greyline SLT5.0, a non-contact ultrasonic flow meter optimized for open channel flow monitoring. After installing a flume in the channel, the SLT 5.0 was used to measure the fluid level in the flume and calculate the flow rate and total flow through the channel.

Part Number Price Available
SLT 5.0A-1-A-1-A-1-A-1-A
Show Configuration
Base Price
Power Input
Standard, 100-240VAC 50/60Hz
Standard, NEMA4X (IP66) fiberglass enclosure
Enclosure Temperature
Standard, -5 to 140°F (-20 to 60°C)
Electronics Protection
Standard, no circuit board coating
PZ32T level sensor, PVC and teflon, 32ft range
Standard, general purpose locations, not rated Intrinsically Safe
Sensor Cable
25ft RG62AU coaxial
Data Logger
Not included
Control Relays
2, standard
$1,745.00 1

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