Economic Upturn?

Maybe. We're seeing signs.

After a best-ever 2008 we saw about a 25% downturn in 2009. 2010 started off equally bad, maybe even worse. Then, April & May were strong - above our 2008 average. We're cautious, though. The two months were helped by unusually large orders from four customers. So - cautiously optimistic!

Another sign - not necessarily good - component shortages and lead times are increasing rapidly - up to 20 weeks. So far we're able to cope, as most of our parts are available from multiple sources.

Such problems aside, let's hope the improvement continues.

Application Note

Detect Thermocouple Failure Without Upsetting the Process

One from the archives. Our customer needed to alarm on thermocouple failure without shutting down the process.

Thermocouple instruments commonly include upscale burnout indication. If the thermocouple breaks or fails open-circuit the instrument's output goes high, just as if the temperature had gone out of control. This often is used to insure failsafe failure, shutting the process down and sounding an alarm.

Our customer, a utility, needed an overtemperature shutdown on a monitored water temperature. They also wanted to trip an alarm upon thermocouple failure but without interrupting the process. We were able to suggest a simple dual-trip alarm setup to do this.

Our thermocouple instruments, like most others, offer a downscale burnout option. (Thermcouple failure causes the output to go low instead of high.) Using a dual-trip alarm, we set trip #1 for HI trip and trip #2 for LO. The HI trip, of course, was used to shut the process down on excessive temperature. The LO trip was set below freezing. Its relay would trip when the thermocouple failed but never under normal operation.

For the full application note, click here.

Our web site - Signal Conditioners, Process Transmitters: http://www.jhtechnology.com/

E-mail: jhtek@jhtechnology.com

Export Sales

Helping the balance of trade -

Although the majority of our sales are within the US we welcome interntional orders. In the past two weeks we've shipped:

• 25 more pieces of a custom assembly (4-input load cell amplifier) for our good OEM customer in Sweden. They buy a few hundred per year - we have an open order for 50 more right now.
• 30 more JH4380W rangeable DC transmitters - specials - with extended temperature ICs to guarantee operation to minus 40 degrees. Although shipped to a US customer, they will be using them in systems exported to Russia. A repeat order - they ordered 54 last year.
• 6 transmitters to an overseas distributor.

 We're grateful for all orders, foreign or domestic.

Current Booster

THE BOOSTER!

Well, ok, not that booster!

Another "rush" special - to boost the current drive from a voltage signal. Our customer needed -10 to +10 volts to drive a 50 milliamp load. The voltage output from their control signal could supply only a fraction of that, so they needed an output-equals-input driver or current booster. They called us.

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  Additional needs: "ASAP - yesterday if possible" because they had just discovered the system problem.
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  Very high accuracy for their test application.

We got lucky. Years ago we solved another customer's high-current requirement by designing a custom circuit board. The requirements were different, but we were able to use that board to assemble the required circuit. It so happened that we had three of those boards left. Our customer needed four, but two could wait. We received the order March 22, shipped the first two March 23 and ordered a few more boards from a quick-turnaround service.

Accuracy? We guaranteed +/-3mV on a 20 volt wide span (+/-0.015% of range).

The customer has now asked us to quote on an 8-channel version.

This one isn't on our web site, but you can see examples of other special & custom signal conditioners at www.jhtechnology.com/customs.

Two Wire Transmitters

Some People Like

Trimpots!

We recently picked up a new customer who ordered a few of our 2-wire thermocouple transmitters. This customer sells thermocouples and other temperature probes, and the manufacturer they represent also offers transmitters from a well-knows European company.

Why did they buy ours? The European brand is computer-ranged. The end user wanted to be able to adjust calibration without needing a computer set-up. So, they bought our "old fashion analog" fixed range Model JH220 - complete with trimpots!

This is at least the second time this has happened. Another of our customers, a temperature sensor manufacturer, ran into exactly the same objection years ago and regularly offers our transmitters even though they also handle the European brand.

Do you need to change ranges but still like trimpots? Model JH225 (shown) adds switches that let you recalibrate to almost any practical range for thermocouple types J, K and T. (You do need a calibration source.) We also offer similar transmitters for RTD (resistance thermometer) sensors.

Links:
Model JH220, thermocouple 2-wire transmitter, fixed range (factory set)
Model JH225, thermocouple 2-wire transmitter, user-rangeable
Model JH240, RTD (resistance thermometer) 2-wire transmitter, fixed range
Model JH245, RTD 2-wire transmitter, user-rangeable

All 2-Wire Transmitters

Simple Specials

Standard Product, Nonstandard Connections

Our OEM customer needed a fully compatible replacement for a thermocouple alarm module they once bought from England. Our Model JH1200 plug-in thermcouple alarm filled the bill, except the pin connections were different.

The answer was simple - take our standard product, unsolder the internal wires from the pins and rewire them to be the same as the British product. And, since the the connections to the thermocouple were changed, we also needed to relocate the temperature sensor used for cold junction compensation.

One more step - we made a simple adapter to allow the converted alarm module to plug into our standard production test and burn-in fixtures.

This customer buys only one or a few at a time, but they've become a regular for several years.

Links: Process Alarms
JH1200 Thermocouple Alarm
Custom & Special Signal Conditioners

Simple Specials

SPECIAL ORDER -

SUM THREE UNEQUAL FLOWS

Flow #1: Full Scale (20mA) = 1.75 MGD (Million Gallons per Day)

Flow #2: Full Scale (20mA) = 22 MGD

Flow #3: Full Scale (20mA) = 1.04 MGD

Module Output: Full Scale (20mA) = 24.79 MGD

Something we do all the time - modify our products to meet out-of-the-ordinary needs. In this case the customer needed to add signals from three flowmeters, each having a different scale factor.

A bit of engineering calculation, followed by the selection of a few precisely-measured input resistors, did the trick.

One piece order. Turn-around time - four days from order entry to shipment.