Resistance temperature probes
Probes already fitted in pockets, tanks and ducts, read without replacing them. Where a new probe is being fitted, the temperature tag is the simpler choice.
Resistance monitoring tag
The ZARC resistance tag reads the resistance of an element connected to it and reports the value in real time. Sensors and instruments often present what they measure as a resistance: temperature probes, level and position senders, sensing cables. The tag turns those into live readings without replacing them, and reports a circuit that has gone open or short. It runs on its own battery and needs no wiring back to a panel.
01
What it reports
The tag reads resistance continuously and reports at the interval set for the site, down to every minute. Each report can carry the current value and the maximum, minimum and average for the interval.
The dashboard shows the reading in ohms, or scaled to the quantity the element represents: degrees for a temperature probe, a percentage for a level or position sender. The scaling is set per input, to the element's own curve.
An open circuit and a short circuit are reported as faults, not as readings. A broken lead or a failed element is told apart from a real change in the thing being measured.
Resistance that drifts is a warning in itself. A heating element, a connection or a probe whose resistance creeps over weeks is on its way out, and the trend shows it.
The tag reads what is already there. It does not replace insulation, earth or electrical safety testing, and it is not connected to live circuits.
02
Applications
Resistance is how a great deal of existing equipment reports itself. The uses below are the common ones.
Tank and fuel level senders
Float senders that vary their resistance with level, on generator day tanks and plant.
Valve, damper and actuator position
Position feedback from a potentiometer, shown as percentage open, so a valve that did not move is seen.
Water sensing cable and tape
Cable that changes resistance when wet, run along a pipe route or around a room.
Loops and tamper circuits
A wired loop through covers, fences or cabinets that goes open when broken.
Heating elements and trace heating
An element whose resistance has drifted, or gone open, before the pipe it protects freezes.
Corrosion probes
Probes that lose metal as the structure does, with resistance rising as they thin. The trend is the corrosion rate.
Legacy instruments
Older instruments with a resistance output and no other way of being read remotely.
Connections that are deteriorating
A joint or contact whose resistance climbs with time, reported before it fails.
03
Where it can go
The tag sits within a lead's reach of the element it reads. Typical positions:
Beside a probe pocket
On the pipe, tank or duct that carries the probe.
At a tank
Next to the level sender's terminals.
On a valve or damper
Beside the actuator's feedback terminals.
In a plant room
At the end of a sensing cable run.
In a cabinet or kiosk
On the loop it watches.
At a test point
Where a corrosion or monitoring probe is terminated.
04
In the dashboard
Every input shows its live value, in ohms or in the units it has been scaled to, with a trend from the last hour to the last year. The dashboard works out the maximum, minimum and average over any period and marks open-circuit and short-circuit faults separately from readings. Records export for maintenance files and audits.
Limits are set per input: high, low, trend and duration. When one is crossed the alert is raised in real time and goes by email or SMS, and through an app where required, to the people you name, with escalation to further contacts.
- Live value for every input, in ohms or scaled units
- Trend graphs from one hour to one year
- Maximum, minimum and average over any period
- Open-circuit and short-circuit faults shown separately
- Slow drift over weeks made visible
- High, low and trend limits per input
- Time spent beyond each limit
- Every alert logged with the reading that raised it
- Records exported for maintenance and audits
- A tag that misses its reporting interval is flagged
05
Industries
Resistance tags are fitted wherever existing probes, senders and loops need to be seen remotely, including:
Industrial and manufacturing
Process probes, valve position and legacy instruments.
Energy and utilities
Corrosion probes, tanks and remote plant.
Facilities management
Probes and senders across building plant.
Data centres and critical infrastructure
Sensing cable, generator tanks and trace heating.
Buildings and estates
Trace heating and plant room loops.
Critical national infrastructure
Loops and probes on unmanned sites.
06
Technical specification
| Parameter | Specification |
|---|---|
| Measurement | Resistance of a connected element, read continuously and reported in real time |
| Input | Wired connection to the element; wiring arrangement to the requirement |
| Units | Ohms, or scaled to the quantity the element represents |
| Scaling | Curve or factor set per input, to the element's own characteristic |
| Values reported | Current value, maximum, minimum and average for each reporting interval |
| Range and accuracy | Specified to the requirement |
| Open and short circuit | Reported as faults, separately from readings |
| Element changes | None; the tag reads the element already fitted |
| Reporting interval | Configurable, down to every minute |
| Limit alerts | High and low limits, set per input |
| Trend alerts | Value drifting at a rate you set |
| Duration alerts | Time beyond a limit, so a brief excursion does not alarm |
| Alert delivery | Dashboard, email or SMS; app where required |
| Recipients | Named people and groups, with escalation to further contacts |
| Gateway power loss | Raises its own platform alert |
| Missed reports | A tag that misses its reporting interval is flagged in the dashboard |
| Dashboard | Live value, trends, max/min/average, faults, drift; configured to your requirement |
| Records | Every reading and fault time-stamped and exportable |
| Data | Full history; UK-hosted or on servers on your own site |
| Power | Internal battery, up to five years as standard; longer with additional cells |
| Radio | 433 MHz, one-way (transmit only) |
| Radio range | Site-dependent; confirmed by site survey |
| Environment | Indoor or outdoor, enclosure specified to the location |
| Mounting | Beside the element, within lead reach |
| Enclosure | Standard or built to the site; bespoke moulding for volume orders |
| Not for | Insulation, earth or electrical safety testing; connection to live circuits |
| Charges | No per-alert, per-user or licence charges |
| Manufacture | Made to order in the UK |
| Certification | CE marked |
07
From requirement to live alerts
Requirement
Tell us the element: what it is, what it measures and its resistance range. A data sheet or a part number is enough.
Configuration
Each tag is built to order for that element, with scaling, reporting interval and limits set.
Fitting
The tag is fixed beside the element and connected to its terminals. Nothing else on the equipment changes.
Commissioning
The reading is checked against the element's known value or a reference, open and short faults are proved, and alert routes are tested.
Ready to get started? Every deployment begins with a site survey.
Book a site survey08
How it reports
Each reading leaves the tag on 433 MHz radio, reaches a ZARC gateway and appears on the dashboard, where scaling and limits are applied. The tag is transmit-only, with no receiver, and independent of any control system the element also feeds, so it adds a remote reading without touching the controls.
Related tags
Temperature
A new probe, where none is fitted.
Tank level
Level by ultrasonic or pressure sensing.
Dry contact
An on or off output, where the signal is a contact.
Leak & water
A point probe for water on a floor.
Questions we answer most.
What does the resistance tag do?
It reads the resistance of a connected element and reports it in real time, in ohms or scaled to the quantity the element represents.
What can be connected to it?
Resistance temperature probes, level and position senders, water sensing cable, loops and other elements that present their state as resistance.
Does it replace the existing sensor?
No. It reads the element already fitted.
Can it show a broken wire?
Yes. Open-circuit and short-circuit conditions are reported as faults, separately from readings.
Can the reading be shown in real units?
Yes. Scaling is set per input, so a probe shows degrees and a sender shows a percentage.
Can it show a slow drift?
Yes. A value creeping over weeks shows on the trend and can raise an alert.
Is it an insulation or earth tester?
No. It does not replace insulation, earth or electrical safety testing.
When should I use the dry contact tag instead?
When the signal is a contact that is open or closed. This tag is for a value that varies.
Does it need power or a network?
No. It runs on an internal battery and reports by radio to a ZARC gateway.
How long does the battery last?
Up to five years as standard, and longer where additional cells are fitted.
Looking for something else?
We work with any sensor for any application.
Most sensing needs are met by a tag we already build, configured for your equipment. If yours needs a sensor or interface we don't list, we have the engineering to build it. Tell us what you need to measure, and we will tell you how we would do it.
Discuss your requirementDiscuss a monitoring
or alerting solution
Tell us what is happening on site, what you need to see, and the event you need to hear about. We will come back with the system that answers it.
Direct contact
Location
Venator House, Unit 9, 15-17 St Stephen's Road, Bournemouth
Dorset, BH2 6LA · VAT GB 409644484
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Contact the engineering team
Direct to the team that designs and builds the range. Tell us the equipment and the event that matters.