The Fieldpiece Dual-Temperature Accessory, model ATH4, measures two temperatures simultaneously using the included k-type, wrap tab beaded thermocouples. The technology inside the ATH4 provides superior temperature compensation in rapidly changing environments commonly found while performing field service. Use the ATH4 to find Delta T and just about any temperature split you want to measure. Displays T1, T2 and T1-T2 on your Fieldpiece meter, handle or data logger. It is included with the HVAC Guide® System Analyzer to get target superheat and for the Target Evaporator Exit Temperature test. Fieldpiece offers a wide variety of k-type thermocouples for various HVAC specific applications. Use pipe clamp T/Cs with the ATH4 to check for blocked filters. Use wet and dry bulb thermocouples to find target superheat.

There are other digital thermometers and dual temperature meters out there. This one is unique. Because of the technology employed inside, the ATH4 offers superior temperature compensation in rapidly changing environments commonly found while performing field service. Meters with thermocouple adapters often take a long time to stabilize due to transfer of ambient heat to the adapter while in a pocket, in the back of your truck, even the heat generated while in your hand. The ATH4, as with all of Fieldpiece's k-type thermometers and meters, stabilizes rapidly so you can take it from the rooftop to the walk-in and get more accurate readings faster than the competition.

How Does It Work?
Converts the voltages from two K-type thermocouples to display temperature on any digital multimeter with industry standard jacks. For 0.1º resolution, use a DMM that displays 0.1mVDC. The ATH4 converts the Fieldpiece stick series meter, DL3 data logger and EHDL1 electronic handle to a one-piece dual-input temperature meter. Use the optional Fieldpiece ADLS2 deluxe silicone test leads or the AHDL1 adapter handle with the ATH4 for use with DMMs with industry standard jacks.


Ensure the temperature being measured is stable. Maintain good contact between the thermocouple and what's being measured. Set the meter on 200mV or 2000mV range for 0.1º or 1º resolution respectively. Slide the switch to "T1" to measure display T1, to "T2" to display T2, and to "T1-T2" to measure the difference between T1 and T2.

Velcro Tie-wrap Instructions

Two Velcro straps have been included with the ATH4 to make it easier to measure pipe temperatures. Use the Velcro strap to hold the bead of the model ATB1 thermocouple against the pipe.

Features and Benefits
  • Field calibration for ±1ºF accuracy
  • Displays ºF directly at 0.1ºF resolution on DMM with 0.1mVDC resolution
  • Select ºF or ºC
  • Converts from -50ºF to 1800ºF (optional thermocouple required for 1800ºF)
  • Includes two "wrap tab" thermocouples plus velcro straps. Thermocouples insulated to 400ºF.
  • Auto-off can be disabled for data logging

What's Included
  • Dual-Temperature Accessory - ATH4
  • (2) K-type wrap tab bead thermocouples - ATB1
  • (2) Velcro Tie- wraps (not pictured)
  • Mini-calibration screwdriver
  • 9V battery (installed)
  • Operator's manual

Read more
Manuals (2)
Temperature Accessory
Switchable: T1 T2 T1-T2 standard male banana plugs
Two externally adjustable pots
Conversion Rate:
1mVDC per 1º
-50 to 1800ºF (-46 to 982°C)
0.1º for meters with 0.1mVDC
Battery Type:
Battery Life:
200 hours continuous
15 minutes
Max Input Voltage:
60 VDC 24 VAC
Operating Temp Range:
-30 to 120ºF (-34 to 49°C)
Probe Insulation:
Teflon to 500ºF (260°C)
Speak with a real person who will go out of their way to help!
Monday – Thursday
8am–5:45pm EST
9am–4:45pm EST
1 Video

    Product Reviews

    Product Q&A