text.skipToContent text.skipToNavigation

Call us at 1-888-826-6342

Call us at 1-888-826-6342.

Portable USB Temperature and Humidity Data Loggers with Display

Portable Temperature/Humidity Data Loggers with Display


Item# OM-71

Volume discounts available
Volume Discount Schedule
Quantity Price each
1-4 $234.11
5-9 $222.40
10-24 $217.72
25-49 $208.36
50-99 $203.68
100+ $198.99

In stock

Lead Time (If not in stock): 2 weeks
Portable Temperature/Humidity Data Loggers with Display OM-71 OM-71
  • Compact, Light Weight, Easy-to-Use
  • User Selectable Stop on Memory Full or Memory Rollover for Continuous Recording
  • PC Delayed Start or Pushbutton Recording Control
  • Read Recorded Data on Logger Display

OM-71 Model Options

View all models

Edit these specs to order a different model. Not all combinations are valid. Options compatible with previous selections will be in bold.

*Highlighted options are not compatible. Please select a different combination.

Measurement Type
Number of Measurements
Input Type
Maximum Samples
Additional Feature
Data Interface
Max Sampling Rate

The OM-70 Series of portable temperature and temperature/humidity data loggers are easy-to use, versatile devices which can be used for a wide range of logging applications including coolers, freezers, greenhouses, museums, laboratories, shipping containers, warehouses, environmental monitoring and food storage.

These data loggers are capable of sampling as fast as once per second or as slow as every 18 hours. Models OM-71 and OM-72 can store a total of 43,344 temperature measurements in memory. Model OM-73 can store a total of 43,344 measurement points for temperature only or 21,672 points of temperature, humidity and dew point. The model OM-74 thermocouple data logger can store 32,638 temperature samples. Easy-to-use Windows software is included with each data logger.

The software is a full-featured program that allows you to set up all data logger functions including sampling rate, logging duration, start mode, logging mode, and high and low temperature alarm values. Once data has been logged, the program then allows you to download data from the logger, plot the data and export the data to an ASCII text or Excel file format for further analysis.

Software Features Include:
• Data summary to read statistics and alarm information in a simplified report format.
• Data listing for tabular view of detailed dates, times and values of recorded data.
• Graph function displays data in clear graphical format.
• Zoom magnifies data with powerful zoom and autoscale functions.
• Autoscale function fits data to the screen or allows user to manually enter their own values.
• Graphical Cursor displays exact data of any point in the graphical display.
• Export data in text or Excel format.
• Print graph or text data with print preview and setup options.
• Logger configuration allows easy set up and launch of data loggers with immediate or delayed start, preferred sample rate, alarm setup, and custom ID.
• Password protected calibration function automatically stores with parameters in device or restores factory defaults. A calibration Window is provided in the software to simplify the calibration procedure.
• Status windows display unique ID of logger, battery voltage, memory used, sample rate, duration, alarm condition and logging status.
• Menu Bar along the top of the screen provides one click access to software functions.

OM-71, OM-72, OM-73
Ambient Temperature Measurement Range
(Models OM-71, OM-73):
-20 to 70°C (-4 to 160°F)
External Sensor Temperature Measurement Range
(Model OM-72):
-40 to 70°C (-40 to 160°F)
Storage Temperature: -40 to 77°C (-40 to 170°F)
Temperature Accuracy: ±0.5°C (±1°F), from -17 to 50°C (1 to 122°F)
Temperature Resolution: 0.1°C (0.05°F)
Relative Humidity Range
(Model OM-73):
0 to 99% RH non-condensing
Relative Humidity Accuracy
(Model OM-73):
±2% RH from 10 to 90% RH @ 25°C (77°F)
Relative Humidity Resolution
(Model OM-73):
0.05% RH

Display Temperature Resolution:
0.1°C (0.2°F) up to 199.9 °C or °F,
1°C (1°F) above 200 °C or °F
Logged Temperature Resolution: 0.1°C (0.2°F)
Thermocouple Impedance: 50 ? max for specified accuracy
Cold Junction Temperature Accuracy: ± 0.3°C (±0.5°F)
Operating Temperature: -18 to 55°C (0 to 131°F)
Storage Temperature:-30 to 80°C (-20 to 175°F)

Sample Rate:
1 second to 18 hours user selectable
Alarm Settings: Over/under alarm with visual indication
LCD Display: Displays temperature, date, time,
alarm condition recording status and battery condition
Time Accuracy: ±100 ppm @ 24°C (75°F)
Measurement Capacity: OM-71, OM-72, OM-73:
Non-volatile memory; 43,344 samples
for temperature only, or 21,672 samples for temperature,
humidity and dew point (Model OM-73); OM-74; 32,638 temperature samples
Recording Control: Start on button press, immediate after setup,
or at a user specified date and time
Recording Mode: Stop on memory full,
or continuous recording with memory rollover
Minimum System Requirements: 8MB of RAM, 2MB of disk space,
800 x 600 resolution, 1 free USB port
Software Compatibility: Windows XP/Vista/7 and 8 (32-bit and 64-bit)
Interface: USB 2.0
Power: OM-71, OM-72, OM-73: 3 V CR2032 lithium battery (included);
OM-74; 3 AAA batteries (alkaline or lithium)
Battery Life: 3 years (average)
OM-71, OM-72, OM-73: 6 H x 5.7 W x 1.3 cm D (2.36 x 2.24 x 0.51')
OM-74: 5.7 H x 5.5 W x 3.0 cm D (2.25 x 2.15 x 1.2')
OM-71, OM-72, OM-73:
91 g (3.2 oz)
OM-74: 62 g (2.2 oz)
loading all models
loading all reviews
Rated 5 out of 5 by from Temperature data logger We have bought these before. They have lasted many years in extreme environments. Only had to change the battery on one unit once.
Date published: 2017-04-12
Rated 4 out of 5 by from Working as described, trying software with WINE We have been using this to monitor the RH in a glove box. It has been working well for that, 0.1% RH is about 25 ppm H2O in our environment. If you don't need single digit ppm H2O measurements, then this is an inexpensive way to monitor a glovebox. The software runs under WINE (Crossover) in Ubuntu 14.04 GNU/Linux. However, it cannot see the datalogger on the USB port. Web searches suggest that you need to set up a link from the appropriate usb port in /dev to the appropriate COM port the dosdevices directory of the WINE bottle in which the datalogger software is running. It should work that way, but I haven't gotten around to testing it. It turns out we don't need the datalogger function very often, we mainly use it for real-time information. The main improvement I would like to see is documentation of the communication protocol so I can talk to the datalogger directly in a GNU/Linux operating system without using WINE.
Date published: 2016-06-03
  • y_2023, m_6, d_10, h_24
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.35
  • cp_2, bvpage2n
  • co_hasreviews, tv_0, tr_10
  • loc_en_US, sid_OM-71, prod, sort_[SortEntry(order=HELPFULNESS, direction=DESCENDING), SortEntry(order=POSITIVE_FEEDBACK, direction=DESCENDING), SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_omega
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getReviews, 19ms
loading all QA

Dear Sir, We are interesting to purchase the product but we need some clarifications for this products, If the equipment is 24/7 working (Recorded) or only particular time working (Auto power off without disturbing the equipment? please advice.

Asked by: Urjita Electronics
When you are setting up the logger you can select either to stop on Memory Full or Memory Rollover for Continuous Recording. Thank you.
Answered by: Application Engineer
Date published: 2019-07-22

Can i use the unit without the pc and when i need to retrive the data i connect it to the pc ?

Asked by: RackMaster
Thank you for your question. The logger needs to be initially configured on the pc using the software. Once it is configured it is totally stand-alone to archive data and than later connected to pc to download the data.
Answered by: Application Engineer PV
Date published: 2021-04-30

When Calibrating the logger (per the user manual), is the new calibration stored within the logger itself or in the software app on the PC?

Asked by: ISS Lab
Thank you for your question. Calibration is stored in the logger.
Answered by: Application Engineer PV
Date published: 2023-05-19

I am looking at the OM-74 for use with a C-type or B-type thermocouple. How many hours do the batteries lasts, are they rechargable?

Asked by: L Rolly
The battery life could be up to 3 years depending on logging interval and the frequency you connect to PC for setup. It is not rechargeable, AAA alkaline or lithium are used.
Answered by: PVDAS
Date published: 2020-02-14

I have an Omega OM-70 series data logger at work. The data transfer cable cannot be found. Can i order another cable?

Asked by: Jake35031
Hello, this logger uses a standard mini USB cable that you can find in any electronics store. You can also order from us the replacement part OM-62-USB-CABLE.
Answered by: DA Engineer
Date published: 2020-02-25

Can I log two separate temps continuously with this one unit? Since you discontinued the OM PL-TT I am looking for a replacement.

Asked by: mark1234
OM-72 has one internal and one external temperature sensor. Other options you can consider are OM-DVT4 or ISD-TC. These are not direct replacements of the OM-PLTT, so please read the spec sheets before making your decision. If you have any question please contact our DAS team at das@omega.com or give us a call and ask for the Data Acquisition group.
Answered by: DA Engineer
Date published: 2019-11-21

I have roughly 30 of these that are used. Do you guys buy them back for remanufacturing?

Asked by: Greenwood
Thank you for your inquiry. Omega does not buy back used equipment for re-manufacturing.
Answered by: Application Engineer JB
Date published: 2022-01-20
  • y_2023, m_6, d_8, h_22CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.35
  • cp_2, bvpage2n
  • co_hasquestionsanswers, tq_15
  • loc_en_US, sid_OM-71, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_omega
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getContent, 72ms
Portable Temperature/Humidity Data Loggers with Display
0 In Stock
Portable Temperature/Humidity Data Loggers with Display
0 In Stock
Save Configuration